Symptoms of pregnancy: What happens first

Do you know the early symptoms of pregnancy? From nausea to fatigue, know what to expect.

By Mayo Clinic Staff

Could you be pregnant? The proof is in the pregnancy test. But even before you miss a period, you might suspect — or hope — that you're pregnant. Know the first signs of pregnancy and why they occur.

Classic pregnancy signs and symptoms

The most common early signs and symptoms of pregnancy might include:

  • Missed period. If you're in your childbearing years and a week or more has passed without the start of an expected menstrual cycle, you might be pregnant. However, this symptom can be misleading if you have an irregular menstrual cycle.
  • Tender, swollen breasts. Early in pregnancy hormonal changes might make your breasts sensitive and sore. The discomfort will likely decrease after a few weeks as your body adjusts to hormonal changes.
  • Nausea with or without vomiting. Morning sickness, which can strike at any time of the day or night, often begins one month after you become pregnant. However, some women feel nausea earlier and some never experience it. While the cause of nausea during pregnancy isn't clear, pregnancy hormones likely play a role.
  • Increased urination. You might find yourself urinating more often than usual. The amount of blood in your body increases during pregnancy, causing your kidneys to process extra fluid that ends up in your bladder.
  • Fatigue. Fatigue also ranks high among early symptoms of pregnancy. During early pregnancy, levels of the hormone progesterone soar — which might make you feel sleepy.

Other pregnancy signs and symptoms

Other less obvious signs and symptoms of pregnancy that you might experience during the first trimester include:

  • Moodiness. The flood of hormones in your body in early pregnancy can make you unusually emotional and weepy. Mood swings also are common.
  • Bloating. Hormonal changes during early pregnancy can cause you to feel bloated, similar to how you might feel at the start of a menstrual period.
  • Light spotting. Sometimes a small amount of light spotting is one of the first signs of pregnancy. Known as implantation bleeding, it happens when the fertilized egg attaches to the lining of the uterus — about 10 to 14 days after conception. Implantation bleeding occurs around the time of a menstrual period. However, not all women have it.
  • Cramping. Some women experience mild uterine cramping early in pregnancy.
  • Constipation. Hormonal changes cause your digestive system to slow down, which can lead to constipation.
  • Food aversions. When you're pregnant, you might become more sensitive to certain odors and your sense of taste might change. Like most other symptoms of pregnancy, these food preferences can be chalked up to hormonal changes.
  • Nasal congestion. Increasing hormone levels and blood production can cause the mucous membranes in your nose to swell, dry out and bleed easily. This might cause you to have a stuffy or runny nose.

Are you really pregnant?

Unfortunately, many of these signs and symptoms aren't unique to pregnancy. Some can indicate that you're getting sick or that your period is about to start. Likewise, you can be pregnant without experiencing many of these symptoms.

Still, if you miss a period and notice some of the above signs or symptoms, take a home pregnancy test or see your health care provider. If your home pregnancy test is positive, make an appointment with your health care provider. The sooner your pregnancy is confirmed, the sooner you can begin prenatal care.

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May 11, 2019

  1. Bastian LA, et al. Clinical manifestations and diagnosis of early pregnancy. https://www.uptodate.com/contents/search. Accessed May 19, 2016.
  2. Lockwood CJ, et al. Initial prenatal assessment and first-trimester prenatal care. https://www.uptodate.com/contents/search. Accessed May 19, 2016.
  3. Norwitz ER, et al. Overview of the etiology and evaluation of vaginal bleeding in pregnant women. https://www.uptodate.com/contents/search. Accessed May 19, 2016.
  4. Moore KL, et al. References and suggested reading. In: Before We Are Born: Essentials of Embryology and Birth Defects. 8th ed. Philadelphia, Pa.: Saunders Elsevier; 2013.
  5. Frequently asked questions. Pregnancy FAQ126. Morning sickness: Nausea and vomiting of pregnancy. American College of Obstetricians and Gynecologists. https://www.acog.org/Patients/FAQs/Morning-Sickness-Nausea-and-Vomiting-of-Pregnancy. Accessed May 19, 2016.
  6. American College of Obstetricians and Gynecologists. Months 1 and 2. In: Your Pregnancy and Childbirth Month to Month. 6th ed. Washington, D.C.: American College of Obstetricians and Gynecologists; 2015.

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