Pregnancy Symptoms by Week: What to Expect from Week 1 to Week 40

A complete week-by-week guide to pregnancy symptoms — what is normal, what is unusual, and when to call your healthcare provider.

Pregnancy symptoms shift dramatically across the three trimesters. Below is a week-by-week tour of what most birthing people experience — keeping in mind that every pregnancy is different, and your timing may vary.

First trimester (weeks 1–13): the foundation

Weeks 4–6 bring missed periods, tender breasts, fatigue that feels like a weighted blanket, and a heightened sense of smell. Weeks 6–9 are often the toughest for nausea (it has nothing to do with mornings — it can hit any time). By weeks 10–12, many people see the nausea ease. The first trimester is also when miscarriage risk is highest; after the 12-week scan with a healthy heartbeat, that risk drops to about 1%.

Second trimester (weeks 14–27): the honeymoon

Energy returns. You may experience the 'pregnancy glow' — increased blood volume gives your skin a healthy flush. Around weeks 16–22 comes the magical first kicks (called quickening). The bump emerges, sleep is usually decent, and most people feel their best. Watch for: round ligament pain (sharp lower-belly twinges), darker pigmentation (linea nigra, areolas), and Braxton-Hicks contractions starting around week 20.

Third trimester (weeks 28–40+): the home stretch

Welcome to the home stretch — and a return of fatigue, this time with the added bonus of physical discomfort. Heartburn, swelling, back pain, frequent urination, restless legs, and sleep that feels impossible. Baby's movements become more visible and powerful. Around weeks 36–38 you'll feel pelvic pressure as baby drops. Watch for symptoms of preeclampsia (severe headache, vision changes, sudden swelling, upper-right belly pain) — these warrant an immediate call.

When to call your provider — at any week

Heavy bleeding, severe abdominal pain, fever over 100.4°F (38°C), severe persistent headache or visual disturbance, reduced or no fetal movement after week 28, signs of preterm labor (regular contractions before 37 weeks), or any gush of fluid. Your provider would rather hear from you ten times than miss something. Trust your instincts.