Deciphering whether you’re experiencing pregnancy symptoms can feel confusing and overwhelming. Is your stomach upset from something you ate, or could it be morning sickness? Are you feeling unusually tired, or just coming down with something? With so many overlapping possibilities, it’s easy to second-guess what your body is telling you.

While no two pregnancies are exactly the same, even for the same woman, certain symptoms may suggest pregnancy. Some can appear before a missed period, while others become noticeable later. Comparing your symptoms with PMS and knowing when to take a pregnancy test can help provide a clearer answer.

Pregnancy Symptoms: What to Watch For

There’s no set timeline for pregnancy symptoms because they vary from person to person and from one pregnancy to the next. Many moms-to-be don’t notice changes in their bodies until several weeks after conception, while others notice symptoms earlier. For example, sensitivity to smell and tender breasts may appear before a missed period for some women, while symptoms such as frequent urination often develop later. Here’s a general timeline of when pregnancy symptoms may begin.

Pregnancy Symptoms Before a Missed Period

Many people think pregnancy symptoms only begin after a missed period, but some symptoms may appear earlier. While these early changes can be associated with pregnancy, many are also common during PMS or have other causes. The following symptoms are sometimes reported before a missed period, but symptoms alone cannot confirm pregnancy.¹

Here are some early symptoms that may appear before a missed period:¹

• Breast changes
• Cramping
• Darkened areolas
• Food cravings or aversions
• Heightened sense of smell
• Headaches or lightheadedness
• Light spotting
• Nausea
• Raised basal body temperature
• Tiredness

For a closer look at when these symptoms may begin and what they can mean, read our guide to the early signs of pregnancy.

Pregnancy Symptoms Week by Week

As mentioned above, many women do not notice symptoms during the earliest weeks of pregnancy. While every pregnancy is different, here’s a general timeline of when common pregnancy symptoms may begin.

Week One of Pregnancy

Although it may seem unusual, healthcare professionals date pregnancy from the first day of your last menstrual period (LMP).² During week 1, you’re having your menstrual period, and conception has not yet occurred. Any fatigue, abdominal cramps, swollen breasts, or lower back pain you experience during this time are related to your menstrual cycle rather than pregnancy.

Related: Cramping in Early Pregnancy: Is It Normal?

Week Two of Pregnancy

Week 2 of pregnancy is when ovulation may occur, although the exact timing varies depending on the length of your menstrual cycle.³ Around this time, you may notice ovulation-related changes such as light spotting, increased libido, changes in cervical mucus, or mild pelvic discomfort. These are signs associated with ovulation rather than pregnancy because conception has not yet occurred.

Related: Ovulation Symptoms and Signs

Week Three of Pregnancy

During week three, fertilization may occur if sperm meets the egg after ovulation.⁴ The fertilized egg then begins traveling through the fallopian tube toward the uterus. Because sperm can survive in the reproductive tract for up to five days, conception may result from sex that occurred several days before ovulation.⁹

Most women do not notice clear pregnancy symptoms during week three. Implantation may occur near the end of this week or during the following week, although the timing varies.⁵ Some women report light spotting or mild cramping around this time. Some women report light spotting or mild cramping around this time. Light spotting, known as implantation bleeding, may occur when the fertilized egg attaches to the uterine lining, although many women notice nothing at all.⁵ Fatigue, breast changes, bloating, or a metallic taste may begin around this time or later, but these symptoms alone cannot confirm pregnancy.

Common Pregnancy Symptoms

As pregnancy progresses, hormonal and physical changes may cause several common pregnancy symptoms.⁶ Not everyone experiences the same signs, and some women have few or no noticeable symptoms. If you’re unsure what you’re experiencing, here are some common pregnancy symptoms that may occur early in pregnancy:

Fatigue

Fatigue is one of the most common early pregnancy symptoms. Many women find themselves feeling unusually tired or needing more sleep than usual, even after a full night’s rest. Rising progesterone levels and the body’s many physical changes during early pregnancy can contribute to this persistent exhaustion.⁶

Related: Tips for Battling Pregnancy Fatigue

Increased Urination

You may find that you’re urinating more often if you’re pregnant. As your blood volume increases during pregnancy, your kidneys filter more blood and produce more urine. This can lead to more frequent trips to the bathroom.⁶

Missed Period

A missed period is one of the most common reasons women take a pregnancy test. If your expected period is a week or more late, pregnancy is one possible explanation. However, a missed period doesn’t always mean you’re pregnant. Irregular menstrual cycles, stress, hormonal changes, illness, and other factors can also delay or stop a period.⁶

Nausea

Despite the name “morning sickness,” pregnancy-related nausea can occur at any time of day. About 7 in 10 pregnant women experience nausea or vomiting during the first trimester, often beginning around six weeks of pregnancy.¹⁰

The exact cause of morning sickness isn’t fully understood, but pregnancy-related hormonal changes are believed to play an important role.¹¹ Human chorionic gonadotropin (hCG), a hormone produced by the placenta soon after implantation, may contribute to nausea and vomiting.^11,12 Women with severe morning sickness, known as hyperemesis gravidarum, often have higher hCG levels and should talk with their healthcare provider.

Related: Ways To Relieve Morning Sickness

Tender or Swollen Breasts

Hormonal changes early in pregnancy may cause the breasts to feel swollen, sore, enlarged, or tender. The areolas, or the areas surrounding the nipples, may also darken.⁶

Can Symptoms Indicate a Twin Pregnancy?

Early in pregnancy, it can be difficult to tell whether you’re carrying one baby or multiples. Some women expecting twins report more severe morning sickness, rapid weight gain, very tender breasts, greater fatigue, a bigger appetite, or showing sooner.⁷ However, these symptoms vary from person to person and can also occur in a singleton pregnancy. An ultrasound is the most reliable way to confirm a twin pregnancy.

Related: Signs You Might Be Having Twins or Multiples

PMS vs. Pregnancy Symptoms: What’s the Difference?

Many early pregnancy symptoms overlap with PMS, so it’s completely normal to wonder what your body is trying to tell you.⁸ While the timing and pattern of symptoms may offer some clues, symptoms alone usually can’t distinguish PMS from pregnancy. The comparison table below highlights some of the most common similarities and differences.

If you’d like to learn more about when these symptoms typically begin, read our guide to the early signs of pregnancy.

When Should You Take a Pregnancy Test?

Symptoms alone cannot confirm pregnancy. Home pregnancy tests detect the pregnancy hormone human chorionic gonadotropin (hCG) in urine and are generally most reliable once your period is due or late. Follow the test instructions carefully. If the result is negative but your period still hasn’t started, consider testing again in several days or contacting your healthcare provider.

Related: When is the Best Time to Take a Pregnancy Test?

Trying to determine whether you’re pregnant can bring a mix of excitement, hope, uncertainty, and worry. Because early pregnancy and PMS can cause many of the same symptoms, it’s not always easy to know what’s going on. Taking a pregnancy test at the appropriate time and reaching out to your healthcare provider when needed can help you get the answers you need and move forward with confidence.