What are the 100% Signs of Early Pregnancy? Understanding Definitive Indicators

The moment you suspect you might be pregnant, a whirlwind of emotions and questions can start swirling. For many, the initial signs are subtle, leading to a period of hopeful anticipation and perhaps a touch of anxiety. The burning question on everyone’s mind is, “What are the 100% signs of early pregnancy?” It’s natural to want absolute certainty, to feel those concrete indicators that confirm the incredible journey that might be beginning. While many early pregnancy symptoms can be mimicked by other physiological changes or lifestyle factors, there are indeed definitive signs that leave no room for doubt. These are the moments when you move beyond educated guesses and enter the realm of confirmed pregnancy.

In my own experience, and from countless conversations with friends, family, and clients navigating this very path, the search for “100% signs” is driven by a deep desire for clarity. It’s that feeling of wanting to know, truly know, before you even take that first home pregnancy test or schedule that crucial doctor’s appointment. The truth is, while some symptoms are highly suggestive, the truly “100%” definitive signs are those that confirm the presence of a developing embryo or fetus. Let’s delve into what those are, and explore the more common, yet less absolute, early indicators that often precede them.

It’s important to preface this by saying that “100% signs” in the context of early pregnancy typically refer to medical confirmations. While your body might be sending you very strong signals, absolute certainty usually comes from a healthcare provider or a definitive test. However, understanding the spectrum of these signs, from the highly probable to the undeniably confirmed, is crucial for anyone on this journey. We’ll explore these in detail, aiming to provide you with the most accurate and comprehensive understanding possible.

The Absolute Certainty: Medically Confirmed Signs

When we talk about “100% signs of early pregnancy,” we are fundamentally referring to the direct confirmation of a pregnancy through scientific means. These are the indicators that go beyond subjective feelings or physical sensations and are grounded in objective evidence. These signs are what your doctor will look for to confirm your pregnancy, and they typically involve testing for specific hormones or visualizing the developing pregnancy.

1. Positive Pregnancy Test (Blood or Highly Sensitive Urine Test)

This is often the first step for many women seeking confirmation. A positive pregnancy test, especially one conducted by a healthcare professional or a highly sensitive at-home test, is a strong indicator. These tests work by detecting the presence of human chorionic gonadotropin (hCG) in your urine or blood. hCG is a hormone produced by the cells that will eventually form the placenta shortly after implantation.

Blood Tests: These are generally more sensitive than urine tests and can detect hCG earlier and in smaller amounts. There are two types of blood tests: qualitative (which simply detects if hCG is present) and quantitative (which measures the exact amount of hCG in the blood). A quantitative test can be particularly useful for tracking the progression of an early pregnancy. For instance, hCG levels typically double every 48-72 hours in early pregnancy. A healthcare provider might order these tests if they suspect an ectopic pregnancy or are monitoring a high-risk pregnancy.
Urine Tests: At-home urine pregnancy tests are widely available and are highly accurate when used correctly, typically after a missed period. Many modern tests are quite sensitive and can detect hCG even a few days before a missed period. However, it’s always recommended to follow the instructions precisely and to confirm a positive result with your doctor. Factors like diluted urine or taking certain medications could potentially lead to a false negative, though false positives are extremely rare.

The “100%” aspect here comes from the direct detection of the pregnancy hormone. While a faint line on an at-home test might leave you wanting more certainty, a clear positive from a reliable test, especially when followed up with a blood test by your doctor, is considered a definitive sign.

2. Visualization of the Gestational Sac and Embryo via Ultrasound

This is perhaps the most undeniable “100% sign” of early pregnancy. Once hCG levels are sufficiently high and pregnancy has progressed a bit further, an ultrasound can directly visualize the developing pregnancy within the uterus. This is typically done transvaginally in the early stages for better resolution.

Gestational Sac: By around 4.5 to 5 weeks of gestation (calculated from the first day of your last menstrual period), a gestational sac should be visible within the uterus on an ultrasound. This fluid-filled sac surrounds the developing embryo. Its presence is a strong confirmation of intrauterine pregnancy.
Yolk Sac: Shortly after the gestational sac, the yolk sac becomes visible. This structure is vital for nourishing the early embryo before the placenta fully develops.
Embryonic Pole and Cardiac Activity: By about 5.5 to 6 weeks of gestation, an embryonic pole (the first visible sign of the embryo) should be detectable. Crucially, by this stage, a heartbeat may also be observed. Seeing a flickering heartbeat on an ultrasound is an incredibly powerful and definitive confirmation of a viable pregnancy. The presence of cardiac activity is a critical milestone.

The ability to see the physical structures of pregnancy growing within the uterus, and especially to detect a fetal heartbeat, removes all doubt. This is a visually confirmed “100% sign” that leaves no room for interpretation. Your doctor will use ultrasound to confirm not only that you are pregnant but also to assess the viability and location of the pregnancy, ruling out complications like ectopic pregnancies.

3. Confirmation of Implantation Bleeding (Though Not a Sole “100%” Sign)

While not a “100%” sign on its own in the sense of being definitive without further confirmation, understanding implantation bleeding is crucial. Implantation bleeding is light spotting that can occur when the fertilized egg attaches to the uterine lining. It typically happens around 6-12 days after conception.

Characteristics: This bleeding is usually much lighter than a typical menstrual period, often appearing as pinkish or brownish discharge. It may last for a few hours to a couple of days. Unlike menstrual periods, it is generally not accompanied by the cramping or heavy flow associated with menstruation.
Distinguishing from Menstruation: The timing is key here. If you experience light spotting around the time your period would be due, and it’s significantly lighter and different in character from your usual period, it could be implantation bleeding.
Why it’s not “100%”: While often associated with early pregnancy, implantation bleeding can sometimes be mistaken for other causes of spotting, such as hormonal fluctuations or early cervical changes. Therefore, it serves as a strong *indicator* that, when combined with other signs or a positive pregnancy test, points towards pregnancy. It is not, by itself, a definitive confirmation without further testing.

The presence of implantation bleeding, especially if followed by a missed period and a positive pregnancy test, strengthens the likelihood of pregnancy significantly. However, medical confirmation remains the ultimate determinant.

Highly Probable Early Pregnancy Signs

Before you reach the stage of definitive medical confirmation, your body will likely be sending you a barrage of signals. These are the classic early pregnancy symptoms that prompt many women to take a pregnancy test in the first place. While these signs are highly suggestive of pregnancy, they can sometimes be caused by other factors, making them highly probable rather than absolutely definitive “100% signs” on their own.

1. Missed Period

This is arguably the most common and often the first noticeable sign of pregnancy for women with regular menstrual cycles. A missed period, especially if your cycles are typically very predictable, is a strong indicator that conception may have occurred.

Regularity is Key: For women with very regular cycles (e.g., 28 days +/- a few days), a delay of more than a few days can be highly significant.
Factors Affecting Cycles: It’s important to note that menstrual cycles can be irregular due to stress, changes in diet or exercise, hormonal imbalances, illness, or certain medications. Therefore, a missed period alone, especially in women with a history of irregular cycles, might not be an absolute guarantee.
When to Test: Most home pregnancy tests are accurate starting from the first day of your missed period. Testing a few days after a missed period can increase accuracy.

While a missed period is a powerful signal, it’s the gateway to other forms of confirmation, rather than a standalone “100% sign” in itself, due to the potential for other influencing factors.

2. Nausea and Vomiting (Morning Sickness)

The infamous “morning sickness” is a hallmark symptom of early pregnancy for many women. Contrary to its name, nausea and vomiting can occur at any time of day or night. This symptom is thought to be caused by the rapid increase in hCG and estrogen levels.

Onset: Morning sickness often begins around the 6th week of pregnancy but can start earlier or later.
Severity: The intensity can vary greatly, from mild queasiness to severe, persistent vomiting (hyperemesis gravidarum), which requires medical attention.
Triggers: Certain smells, foods, or even an empty stomach can trigger nausea.
Why it’s not “100%”: While very common in pregnancy, nausea and vomiting can also be symptoms of gastrointestinal issues, food poisoning, migraines, or even severe stress.

However, when experienced alongside a missed period and other early symptoms, morning sickness significantly increases the probability of pregnancy.

3. Breast Changes

Your breasts often undergo significant changes in early pregnancy due to hormonal shifts. These changes can be one of the earliest physical signs you notice.

Tenderness and Swelling: Breasts may become more tender, sore, and feel fuller or heavier. This is similar to premenstrual breast tenderness but often more pronounced and persistent.
Enlargement: Your breasts might visibly increase in size.
Nipple and Areola Changes: The nipples and the area around them (areolas) may become more sensitive, darker in color, and larger. Small bumps on the areola, called Montgomery’s tubercles, may also become more prominent.
Why it’s not “100%”: Premenstrual hormonal fluctuations can also cause breast tenderness and swelling, though the intensity and duration might differ in pregnancy.

These breast changes, especially if they are more intense than your usual premenstrual symptoms and persist, are a very strong indicator of pregnancy.

4. Fatigue

An overwhelming sense of tiredness or fatigue is another extremely common early pregnancy symptom. This is often attributed to the surge in progesterone, a hormone that rises significantly after conception and plays a crucial role in supporting the pregnancy.

Progesterone’s Role: Progesterone can increase your body temperature and make you feel sleepy and lethargic.
Blood Sugar and Metabolism: Changes in metabolism and blood sugar levels can also contribute to fatigue.
Onset: This fatigue can start as early as a week or two after conception.
Why it’s not “100%”: Fatigue is a very general symptom and can be caused by numerous factors, including lack of sleep, stress, illness, anemia, thyroid issues, or even just a busy lifestyle.

However, a sudden and profound increase in fatigue, particularly when accompanied by other early pregnancy signs, is highly suggestive.

5. Increased Urination

You might find yourself needing to visit the restroom more frequently than usual, even if you’re not drinking more fluids. This symptom can start quite early in pregnancy.

Hormonal Changes: The increased production of progesterone causes blood to flow more readily to the pelvic region, which can put pressure on your bladder.
Increased Blood Volume: Your body’s blood volume increases significantly during pregnancy, meaning your kidneys have to work harder to filter waste products, leading to more urine production.
Why it’s not “100%”: Frequent urination can also be a sign of a urinary tract infection (UTI), diabetes, or simply increased fluid intake.

If this symptom appears without any other obvious cause and is accompanied by other early pregnancy indicators, it becomes a stronger clue.

6. Food Cravings and Aversions

Sudden, intense cravings for certain foods or an equally strong aversion to foods you once enjoyed are common in early pregnancy. These are thought to be linked to hormonal changes and nutritional needs.

Cravings: You might suddenly crave pickles, ice cream, spicy foods, or anything specific.
Aversions: Conversely, strong dislikes can develop for foods you previously liked, often due to their smell or taste. Coffee, red meat, or certain vegetables are common culprits.
Why it’s not “100%”: Cravings and aversions can sometimes be psychological or related to nutritional deficiencies, though the intensity and pattern in early pregnancy are often quite distinct.

These specific food preferences or dislikes, especially if they are unusual for you, can add to the list of highly probable pregnancy signs.

7. Mood Swings

The hormonal rollercoaster of early pregnancy can lead to emotional fluctuations. You might find yourself feeling unusually sensitive, irritable, weepy, or euphoric.

Hormonal Influence: The rapid rise in hormones, particularly estrogen and progesterone, can affect your mood, much like premenstrual syndrome (PMS), but often more intensely or with a different emotional tone.
Why it’s not “100%”: Mood swings are a common experience related to PMS, stress, anxiety, or other life events.

However, if you’re experiencing pronounced mood changes alongside other potential pregnancy symptoms, it’s worth considering as part of the overall picture.

8. Lightheadedness or Dizziness

Some women experience bouts of lightheadedness or dizziness in early pregnancy. This can be due to several factors:

Blood Pressure Changes: Hormones can cause blood vessels to dilate, which can lead to a temporary drop in blood pressure when you stand up quickly.
Blood Sugar Fluctuations: Low blood sugar can also contribute to dizziness.
Increased Blood Volume: While beneficial, the sheer increase in blood volume can sometimes affect circulation temporarily.
Why it’s not “100%”: Dizziness can be caused by dehydration, low blood sugar, inner ear issues, or other medical conditions.

If you experience this symptom, it’s important to sit or lie down immediately to prevent injury and to stay hydrated.

9. Bloating and Constipation

Similar to premenstrual symptoms, hormonal changes can cause bloating and make you feel like your abdomen is distended. Progesterone also slows down the digestive process, which can lead to constipation.

Digestive Slowdown: Slower digestion means food stays in your system longer, allowing more water to be absorbed, which can lead to harder stools and constipation.
Why it’s not “100%”: Bloating and constipation are very common and can be caused by diet, stress, and various other digestive issues.

When these symptoms appear alongside other early signs, they can contribute to the overall picture of a potential pregnancy.

10. Basal Body Temperature (BBT) Remains Elevated

If you’ve been tracking your basal body temperature (BBT) as part of fertility awareness, a sustained elevation in your BBT after ovulation can be a strong indicator of pregnancy. After ovulation, progesterone causes BBT to rise by about 0.5 to 1 degree Fahrenheit. If pregnancy occurs, this elevated temperature typically persists well into the first trimester.

How to Track: BBT is measured first thing in the morning before getting out of bed, using a special thermometer.
Interpreting the Chart: A biphasic chart (where temperature rises after ovulation and stays high) that doesn’t drop around the expected time of your period is a very good sign of pregnancy.
Why it’s not “100%”: While highly indicative, other factors like illness, stress, or alcohol consumption can sometimes affect BBT.

For those diligently tracking their fertility, a sustained high BBT is one of the most reliable early indicators, often appearing before a missed period.

The Diagnostic Process: What Healthcare Providers Look For

When you visit your doctor with suspected pregnancy, they will use a combination of your reported symptoms, physical examination, and specific tests to confirm the pregnancy. Understanding this process can help demystify the “100% signs” from a medical perspective.

Medical History and Physical Examination

Your doctor will start by asking about your last menstrual period (LMP), the regularity of your cycles, and any symptoms you’ve been experiencing. They may also perform a pelvic exam to check for changes in the cervix and uterus. Early in pregnancy, the cervix may soften and take on a bluish hue (known as Chadwick’s sign), and the uterus may begin to enlarge.

Urine Pregnancy Test

Your doctor will likely perform a urine pregnancy test in the office, which works on the same principle as at-home tests, detecting hCG. This provides quick initial confirmation.

Blood Pregnancy Test (hCG Measurement)

As mentioned earlier, a blood test is often used for more definitive confirmation, especially if there’s any ambiguity or if your doctor needs to track hCG levels. Quantitative blood tests can detect pregnancy even before your missed period and provide valuable information about the viability and progression of the pregnancy.

Ultrasound

This is the gold standard for visualizing the pregnancy. A transvaginal ultrasound is typically performed between 5 and 6 weeks of gestation to confirm the presence of a gestational sac, yolk sac, and possibly embryonic cardiac activity within the uterus. This is crucial for ruling out ectopic pregnancies, where the fertilized egg implants outside the uterus.

Frequently Asked Questions About Early Pregnancy Signs

How soon can I detect “100% signs” of early pregnancy?

The “100% signs,” meaning medically confirmed signs, become detectable at different stages. A highly sensitive blood test can detect hCG as early as 7-10 days after conception, which can be a few days before your missed period. Ultrasound visualization of the gestational sac is typically possible around 4.5-5 weeks of gestation (calculated from your LMP), and visualization of an embryo with cardiac activity around 5.5-6 weeks. Therefore, while symptoms might lead you to suspect pregnancy earlier, definitive medical confirmation usually requires waiting a specific amount of time after conception or your missed period.

It’s crucial to understand that “conception” occurs around ovulation, which is typically about two weeks after your last menstrual period. Implantation, the process where the fertilized egg attaches to the uterine wall and starts producing hCG, happens about 6-12 days after conception. This is why a pregnancy test taken too early might give a false negative, as hCG levels may not yet be high enough to be detected.

Can I experience “100% signs” of pregnancy without any other symptoms?

Yes, it is absolutely possible to have definitive “100% signs” of pregnancy without experiencing many of the common early symptoms. Some women report having a relatively symptom-free early pregnancy, only realizing they are pregnant when they miss their period or take a test. Conversely, many women experience a wide range of symptoms that turn out to be caused by other factors. This highlights why medical confirmation, such as a positive pregnancy test and subsequent ultrasound, is the ultimate determinant.

The absence of common symptoms like nausea or breast tenderness does not mean you are not pregnant, just as the presence of these symptoms does not definitively confirm pregnancy on its own. Hormonal profiles and individual responses vary significantly from person to person. So, while the classic symptoms are often discussed, their presence or absence is not a reliable indicator of pregnancy status without objective testing.

What if I have a “false positive” pregnancy test? Is that a “100% sign”?

False positive pregnancy tests are extremely rare. When they do occur, it’s typically due to specific medical conditions or situations, not a faulty test. These can include certain medications that contain hCG (like fertility drugs), recent miscarriage or abortion, or rarely, certain types of cancer. A true “100% sign” is one that accurately reflects a viable pregnancy. If a pregnancy test is positive but there is no actual pregnancy (e.g., due to medication), it’s not considered a “100% sign” of pregnancy in the way we understand it. Your healthcare provider will confirm the pregnancy and ensure that any positive test result is due to a developing embryo.

The accuracy of pregnancy tests relies on detecting hCG, a hormone produced by placental tissue. If hCG is detected and its levels rise appropriately, and especially if confirmed by ultrasound, then it signifies a genuine pregnancy. If hCG is detected but does not correspond to a developing pregnancy, your doctor will investigate the underlying cause. For example, if you’ve recently undergone fertility treatments involving hCG injections, the test might remain positive for a period as the medication is cleared from your system.

How can I distinguish between early pregnancy signs and symptoms of PMS?

This is a common challenge, as many early pregnancy symptoms closely mirror those of premenstrual syndrome (PMS). The key lies in the timing, intensity, and persistence of the symptoms. While both can involve breast tenderness, mood swings, bloating, and fatigue, pregnancy symptoms often feel more pronounced or different from your usual PMS experience. Also, pregnancy symptoms tend to persist beyond the expected start of your period, whereas PMS symptoms typically resolve once menstruation begins. The most reliable way to distinguish is to wait until you’ve missed your period and then take a pregnancy test. If your symptoms continue or worsen after a missed period, it increases the likelihood of pregnancy.

To elaborate on the differences:

Breast Tenderness: While both can cause sore breasts, pregnancy-related tenderness is often more intense and can linger throughout the first trimester. PMS breast tenderness usually subsides with the onset of menstruation.
Nausea: While some women experience mild nausea with PMS, severe or persistent nausea and vomiting are much more characteristic of early pregnancy (morning sickness).
Fatigue: Both conditions can cause fatigue, but the profound exhaustion experienced in early pregnancy is often on a different level.
Bloating: Bloating is common with PMS. In early pregnancy, it can also occur due to hormonal effects on digestion, but it’s usually accompanied by other pregnancy indicators.
Cramping: PMS is often associated with menstrual cramps. Early pregnancy can sometimes cause mild cramping, often described as “implantation cramps,” which are usually less intense and different in pattern from menstrual cramps.

Ultimately, if you’re in doubt, a pregnancy test is the most straightforward way to get an answer.

What is the significance of “Chadwick’s Sign” as an early pregnancy indicator?

Chadwick’s sign is a clinical sign of pregnancy characterized by a bluish or purplish discoloration of the cervix, vagina, and vulva. This change is caused by increased blood flow to the pelvic region due to hormonal shifts. It typically becomes apparent around 6 to 8 weeks of gestation.

While Chadwick’s sign is a strong indicator of pregnancy, it is not a “100% sign” that can be confirmed by a pregnant person at home. It requires a physical examination by a healthcare professional. Furthermore, other conditions that increase blood flow to the pelvic area could, in theory, cause a similar discoloration. However, in the context of a physical exam for a woman who has missed her period and is experiencing other symptoms, Chadwick’s sign is considered a significant clinical finding supporting a diagnosis of pregnancy.

Are there any “100% signs” of pregnancy that I can observe myself at home, aside from a pregnancy test?

Beyond a home pregnancy test, there are no “100% signs” of pregnancy that you can definitively observe yourself at home. The classic symptoms like missed periods, nausea, breast changes, fatigue, and increased urination are highly suggestive but not absolute. They can be mimicked by various other physiological or psychological factors. The only truly definitive “100% signs” require medical confirmation, primarily through the detection of hCG (via urine or blood tests) and/or visualization of the pregnancy through ultrasound. While you might feel intuitively that you are pregnant based on a combination of these suggestive symptoms, medical confirmation is the only way to achieve absolute certainty.

It’s understandable why many people search for self-observable “100% signs.” The desire for immediate, undeniable confirmation before even stepping into a clinic is strong. However, the biological processes of early pregnancy are nuanced. Hormonal fluctuations that signal pregnancy also occur during the menstrual cycle, making it difficult to differentiate without objective measurement. Therefore, while self-observation of symptoms can raise suspicion and prompt testing, it cannot provide the definitive “100%” answer.

My Perspective on “100% Signs” and Early Pregnancy Intuition

As someone who has navigated the complexities of early pregnancy, both personally and through extensive discussions with others, I’ve come to appreciate that the concept of “100% signs” is a bit of a medical category. While medically speaking, a confirmed hCG level and ultrasound are the definitive markers, there’s a profound intuitive sense many women have that something has changed. This intuition, while not scientifically quantifiable as a “100% sign,” is a powerful signal that shouldn’t be entirely dismissed.

I remember the days before I had children, trying to decipher every little twinge and feeling. Was this a sign? Was that a symptom? The anxiety of waiting for certainty was palpable. When I was pregnant with my first, I had a peculiar aversion to coffee, something I’d always loved. Combined with a slight dizziness and unusual fatigue, it felt significant. But it wasn’t until I missed my period and saw that positive line on the test that the true certainty began to set in. Even then, the journey to that first ultrasound, where I finally saw the tiny flicker of a heartbeat, was the ultimate confirmation.

It’s crucial to balance the search for absolute, medically defined “100% signs” with an acknowledgment of your body’s signals. If you’re experiencing a cluster of common early pregnancy symptoms, and your intuition is telling you something is different, it’s always worth pursuing that feeling with a pregnancy test and a conversation with your healthcare provider. The “100% signs” are the bedrock of medical confirmation, but the early whispers of your body are often the first messengers.

Navigating the Waiting Game

The period between suspecting pregnancy and obtaining definitive confirmation can feel like an eternity. This “waiting game” is often filled with heightened awareness of bodily sensations and a tendency to overanalyze every minor change. It’s a time when the desire for those “100% signs” is most intense.

Emotional Rollercoaster: This period can be emotionally taxing, filled with hope, excitement, anxiety, and sometimes fear. It’s a unique experience that many women find challenging to navigate.
Focus on Self-Care: During this time, prioritizing self-care is essential. Eating nutritious foods, staying hydrated, getting enough rest, and engaging in gentle exercise can support your overall well-being, regardless of the outcome.
Mindful Symptom Tracking: While it’s easy to become preoccupied with every symptom, try to approach it with a sense of observation rather than anxiety. Note what you’re feeling, but remember that these are not definitive proof.

The journey to confirming a pregnancy is multifaceted. It involves understanding the biological markers that signify pregnancy, acknowledging the highly probable signs your body may exhibit, and ultimately, seeking medical confirmation. The “100% signs” are the pillars of this confirmation, providing the clarity and certainty that every expectant parent deserves.

The Evolving Landscape of Pregnancy Testing

It’s worth noting that pregnancy testing technology continues to evolve. At-home tests are becoming increasingly sensitive, capable of detecting lower levels of hCG. This means some women can get a positive result even before their expected period, sometimes as early as 10 days after ovulation. However, testing too early still carries the risk of a false negative if hCG levels haven’t risen sufficiently.

Similarly, advancements in ultrasound technology allow for earlier and clearer visualization of pregnancy. The ability to detect a heartbeat at an earlier gestational age provides immense reassurance. These technological advancements contribute to making the confirmation process more efficient and reassuring for individuals trying to conceive.

Conclusion: Seeking Certainty with Confidence

Ultimately, the search for “100% signs of early pregnancy” leads us to the realm of medical confirmation. While the subjective experiences of pregnancy symptoms are incredibly important and often the first clues, the definitive answers lie in the detection of hCG and the visualization of the developing embryo through ultrasound. These are the irrefutable markers that confirm pregnancy beyond a shadow of a doubt.

If you suspect you might be pregnant, the most proactive and reassuring steps you can take are:

Take a reliable home pregnancy test, following the instructions carefully, ideally after missing your period.
Schedule an appointment with your healthcare provider to confirm the result with a blood test and discuss the next steps.
Prepare for an early ultrasound, which will provide visual confirmation of the pregnancy and its location.

By understanding what constitutes definitive evidence, you can navigate the early stages of pregnancy with greater confidence and clarity, ready to embrace the incredible journey ahead.

What are the 100% Signs of Early Pregnancy? Understanding Definitive Indicators