Many people know classic signs like a missed period or morning sickness, but other physical changes can appear even earlier. Below are 10 common early signs of pregnancy you may notice during the first trimester (the first 13 weeks)—read on to see which symptoms often show up earliest and when to consider taking a pregnancy test.

When do pregnancy symptoms start?

Many people begin to notice early pregnancy symptoms around four to six weeks after the start of their last period (that’s roughly one to two weeks after a missed period). Some changes — like light spotting from implantation — can happen earlier, about 5–14 days after fertilization (a week or so after conception).

Understanding the early signs of pregnancy can help you recognize the changes your body is going through.

Symptoms and timing vary because gestational age (pregnancy weeks counted from your last period) and conceptional age (days since fertilization) are different measures. If you notice several early signs of pregnancy — for example, fatigue plus breast changes and a missed period — it’s reasonable to take a pregnancy test. If a test is positive or you have concerns, contact your doctor or gynecologist to arrange confirmation and care.

Early Pregnancy Symptoms

Missed Period

  1. A missed period is often the first obvious sign of pregnancy for people who get regular cycles. If your period is a week or more late, consider taking a pregnancy test — missed periods can also happen for other reasons, so a test or doctor visit can help confirm the cause.

Light bleeding or spotting

  1. Some people notice light spotting (implantation bleeding) when the fertilized egg attaches to the uterus. This commonly happens about 5–14 days after fertilization and is usually lighter than a period. If bleeding is heavy or accompanied by severe pain, seek medical care.

Breast changes or tenderness

  1. Hormonal changes early in pregnancy can make your breasts sore, swollen, or more sensitive. The areola may darken or enlarge. These breast changes often start a few weeks after conception and are a common early sign.

Morning sickness or nausea

  1. Nausea (often called morning sickness) typically begins in the first trimester, commonly around weeks four to six, though it can start earlier or later. It may occur any time of day and ranges from mild queasiness to vomiting. If vomiting is severe or you cannot keep fluids down, contact your gynecologist about treatment options for hyperemesis gravidarum.

Increased urination

  1. Higher blood volume and hormonal shifts mean your kidneys process more fluid, so needing to urinate more often is common—especially early in pregnancy and again later as the uterus grows. If urination is painful or you have fever, contact your doctor (it could signal a urinary tract infection).

Fatigue

  1. Rising progesterone and changes in energy metabolism can cause pronounced tiredness in the first trimester. Rest when you can, eat regular small meals, and talk to your provider if fatigue is extreme or interferes with daily life.

Mood swings

  1. Hormone shifts (estrogen and progesterone) can make emotions feel more intense. Mood swings are common; if you feel persistently depressed or overwhelmed, reach out to your healthcare provider for support.

Food cravings or aversions

  1. Changes to taste and smell are common early in pregnancy and can cause strong cravings or sudden aversions to certain foods. If smell sensitivity triggers nausea, try bland foods or fresh air to ease symptoms.

Cramping or bloating

  1. Mild cramping and bloating can feel like pre-period symptoms and may occur with implantation. Hormonal changes also slow digestion, which can cause constipation and abdominal fullness. Seek care if pain is severe or unusual.

Headaches or backaches

  1. Headaches and lower-back aches are common in early pregnancy. Increased blood flow, changing hormones, and sinus congestion can all contribute. If headaches are severe, sudden, or accompanied by vision changes or swelling, seek immediate medical attention.

Other Early Signs of Pregnancy

Some additional symptoms may show up in early pregnancy. Below are brief explanations and simple self-care tips where relevant.

  • Constipation — Hormone changes in early pregnancy can slow digestion and cause constipation. Staying hydrated, eating fiber-rich foods, and light exercise can help; talk to your provider before taking any laxatives.
  • Smell sensitivity — Many people notice a stronger sense of smell early in pregnancy, which can trigger nausea or sudden aversions to certain food odors. Try fresh air, bland snacks, or avoiding strong-smelling foods if you become queasy.
  • Heartburn — Pregnancy hormones relax the valve between the stomach and esophagus, which can cause heartburn or reflux. Eat smaller meals, avoid spicy or fatty foods, and ask your doctor which antacids are safe if symptoms persist.
  • Nasal congestion — Increased blood flow and hormonal shifts can cause mild nasal stuffiness or sinus symptoms in early pregnancy. Saline sprays and humidifiers are usually safe and can provide relief; contact your provider for severe congestion.
  • Increased heart rate — A mild rise in resting heart rate can occur as blood volume increases to support the pregnancy. If you notice rapid heartbeat, dizziness, chest pain, or fainting, seek medical attention promptly.

How to Know If You’re Pregnant

Many early pregnancy symptoms overlap with pre-period signs, and some people have no symptoms at all. Symptoms alone don’t confirm pregnancy — they’re signals to consider testing or seeking care.

If you’re trying to conceive or have confirmed pregnancy, start a prenatal vitamin with folic acid as recommended to support early fetal development and reduce the risk of neural tube defects. Talk to your doctor or care provider for personalized advice.

Pregnancy Tests

At-home urine pregnancy tests detect the pregnancy hormone hCG and are most reliable when used about one week after a missed period. For best sensitivity, use first-morning urine or follow the test manufacturer’s timing instructions. If your first at-home pregnancy test is negative but your period still hasn’t started, wait a few days and test again.

If an at-home test is positive, make an appointment with your gynecologist or care provider to confirm the result and begin prenatal care. A healthcare professional can order a blood test (quantitative hCG), which can detect pregnancy earlier than a urine test and help evaluate how pregnancy hormones are rising.

When to call a doctor: seek prompt medical care for heavy bleeding, severe abdominal pain, fainting, high fever, or any sudden, severe symptoms. If you have questions about testing timing, prenatal vitamins, or next steps after a positive test, contact your provider for guidance and to arrange appropriate care.