Guide
Pregnancy, trimester by trimester
Last updated: July 2026
Pregnancy is usually counted in three stages, called trimesters. Each one feels different and asks different things of you. Here is a plain map of what tends to happen and what to do, so you know roughly what is ahead.
First trimester: weeks 1 to 12
The baby's major organs are forming. You may feel very tired, nauseous, and emotional, or you may feel little at all, both are normal. Start folic acid if you have not, book your first antenatal appointment (your first pregnancy check-up with a doctor or midwife) early, and be gentle with yourself. Your first scan is often around weeks 8 to 12.
Second trimester: weeks 13 to 27
Often the most comfortable stage. Sickness usually eases and energy returns. You will start to show, and somewhere around weeks 18 to 22 comes the anomaly scan, a detailed scan that checks how your baby is developing. Many women feel the first flutters of movement in this stage. A good time to plan and rest before the busier weeks.
Third trimester: weeks 28 to birth
The baby grows quickly and you may feel it, more tiredness, backache, heartburn, and broken sleep. Watch your baby's movements and report any change. Pack your hospital bag by about week 36, write your birth plan, and learn the signs of labour and when to go in.
When to see a doctor, at any stage
Bleeding, severe or persistent pain, a high fever, severe vomiting, a bad headache with vision changes or swelling, or reduced baby movements later on. When you are unsure, always call, that is what they are there for.
Common questions
What are the three trimesters of pregnancy?
When should I have my first antenatal appointment?
Go further
The First Pregnancy Plan
A community for all pregnant women, week-by-week support, and a midwife or doctor to ask.
See the program →