What are first trimester symptoms?

Bottom lineFirst trimester symptoms (weeks 1 to 12) include nausea and vomiting (often weeks 6 to 12), profound fatigue, tender breasts, frequent urination, food aversions and cravings, mood changes, mild cramping, more discharge, constipation, and headaches, driven by rising hCG, estrogen, and progesterone; see a doctor for severe vomiting that prevents keeping fluids down, bleeding, severe one-sided pain, or fever.

The first trimester (weeks 1 to 12) brings big hormonal changes, and symptoms can be intense even though there's little outward change yet.

Common symptoms

• Nausea and vomiting ("morning sickness"), often weeks 6 to 12, any time of day
• Tiredness and fatigue - often profound
• Tender, swollen breasts
• Needing to pee more often
• Food aversions and cravings, heightened sense of smell
• Mood changes
• Mild cramping and more discharge
• Constipation and bloating
• Headaches and dizziness

Why it happens

Rapidly rising hCG, estrogen, and progesterone drive most of these symptoms. They often ease as the second trimester begins.

Self-care that helps

• Small, frequent bland meals and ginger for nausea
• Rest and hydration
• Prenatal vitamins with folic acid

When to see a doctor

• Severe vomiting that prevents keeping fluids down (possible hyperemesis gravidarum)
• Bleeding or severe one-sided pain (to rule out miscarriage or ectopic pregnancy)
• Fever or feeling very unwell
• Any concern - early pregnancy care matters

Track symptoms and dates, and read our healthy pregnancy guide and use the Pregnancy Week Calculator.

Femora helps you log early pregnancy symptoms and dates to share with your clinician.