First Trimester Symptoms, Tests and What to Expect
Reviewed by Safi Allah Khan
Medically reviewed by: Safi Allah Khan · Written by the Momi team · Last updated 20 October 2026
Quick answer: Common first trimester symptoms are a missed period, nausea or vomiting, tiredness, sore or swollen breasts, needing to pee more, bloating, mood swings and food cravings or aversions. Most start between weeks 4 and 9 and ease by about 12 to 14 weeks. Heavy bleeding or severe one-sided pain needs urgent care.
The first trimester runs from the first day of your last period to the end of week 13. If you've just found out, use How Many Weeks Pregnant Am I? to find your week and the due date calculator for your estimated due date.
Common first trimester symptoms
Rising levels of hormones such as hCG and progesterone cause most early pregnancy symptoms. Mayo Clinic lists these as the most common:
| Symptom | What it's like | Usually starts |
|---|---|---|
| Missed period | Often the first sign | Week 4 to 5 |
| Tiredness | Feeling exhausted, needing naps | Week 4 to 8 |
| Sore, swollen breasts | Tender, heavy, darker nipples | Week 4 to 6 |
| Nausea, with or without vomiting | Can happen at any time of day | Before week 9 |
| Peeing more often | Getting up at night | Week 6 to 8 |
| Bloating and constipation | Slower digestion | Week 6 onwards |
| Food cravings or aversions | Strong dislikes, metallic taste | Week 6 onwards |
| Mood swings | Feeling emotional or tearful | Any time |
| Heartburn | Burning feeling in the chest | Any time |
| Light spotting | A small amount, often around week 4 | Week 4 |
Everyone is different. You may have all of these, a few, or almost none. For when early signs can appear even before a test, see early pregnancy symptoms, and for the full nine months, pregnancy symptoms week by week.
When do first trimester symptoms end?
For most people, the worst is over by the end of the first trimester. ACOG says nausea usually starts before 9 weeks and is gone by 14 weeks for most. The NHS says morning sickness usually clears by 16 to 20 weeks, so it's normal if yours lasts a bit longer. Tiredness also tends to lift in the second trimester, then can return later on.
First appointments and screening
The first trimester is busy for appointments. Typical timings:
| When | What | Notes |
|---|---|---|
| As soon as you know | Contact your provider or midwife | Start folic acid if you haven't |
| Before 10 weeks (ACOG) or 8–12 weeks (NHS) | First prenatal or booking visit | Health history, blood tests, blood pressure |
| 10–14 weeks | Dating scan | Checks your due date and how many babies |
| 10–14 weeks | Screening tests, if you choose | Combined test or cell-free DNA |
The NHS dating scan is usually between 10 and 14 weeks. Screening is your choice. Read first trimester screening and the full pregnancy appointment schedule.
Tips for tiredness and nausea
For nausea (ACOG and NHS tips):
- Eat small, frequent meals or snacks, and don't let your stomach get empty.
- Try plain foods such as crackers or toast, especially before getting up.
- Sip fluids little and often through the day.
- Avoid smells and foods that set you off.
- Ginger and acupressure wristbands may help some people.
- Ask your provider about treatment if self-care isn't enough. Safe medicines exist.
See the full morning sickness guide.
For tiredness (NHS tips):
- Rest when you can and go to bed earlier.
- Accept help with chores or other children.
- Keep gently active if you feel able; a short walk can help.
- Eat regular, balanced meals.
First trimester warning signs
Most first trimester symptoms are uncomfortable but normal. Some need help.
Get urgent help (call your emergency number or go to A&E/ER) if you have:
- heavy bleeding, or bleeding with clots
- severe pain in your tummy, especially on one side
- pain in the tip of your shoulder
- fainting or feeling very dizzy
ACOG notes that these can be signs of an ectopic pregnancy, which needs emergency treatment.
Contact your midwife or doctor the same day if you have:
- any vaginal bleeding or spotting that worries you
- vomiting so often you can't keep fluids down, or very dark pee
- a high temperature
- pain or burning when you pee
The NHS says bleeding in early pregnancy is common and doesn't always mean a problem, but you should always get it checked.
First vs second trimester symptoms
| First trimester | Second trimester |
|---|---|
| Nausea and vomiting | Usually easing |
| Extreme tiredness | More energy for many |
| Sore breasts | Breasts growing, less tender |
| Peeing often | May ease a little |
| Little or no bump | Bump starts to show |
| No movements yet | First movements, 16–24 weeks |
| — | New: backache, heartburn, skin changes, leg cramps |
How Momi helps
Momi follows you from the first trimester: set your due date from your last period or conception date and see your week, trimester and baby size every day. Add your first appointments with medicine reminders, log your weight, and keep a diary of how you're feeling. Each week brings tips and articles for that stage.
Download Momi free on the App Store or Google Play. Free with ads; optional Premium.
Related: pregnancy trimesters · 8 weeks pregnant
Sources
- Mayo Clinic, 1st trimester pregnancy: What to expect
- ACOG, Morning Sickness: Nausea and Vomiting of Pregnancy
- NHS, Vomiting and morning sickness
- NHS, Tiredness and sleep problems
- NHS, Vaginal bleeding in pregnancy
- ACOG, Ectopic Pregnancy
- NHS, 12-week scan
Medical disclaimer: Momi and this website provide general information, not medical advice. Always talk to your doctor or midwife; in an emergency call your local emergency number.
FAQ
When do first trimester symptoms start?
Many people notice the first signs around week 4 to 6, counted from the first day of the last period, with a missed period usually being the first. Nausea often starts before 9 weeks. Some people have very few symptoms at all, which can also be normal.
When do first trimester symptoms end?
For most people, nausea and tiredness start to ease between about 12 and 14 weeks. ACOG says morning sickness is gone by 14 weeks for most, while the NHS says it can last until 16 to 20 weeks for some. A few people have symptoms for longer.
Is it normal to have no symptoms in the first trimester?
Yes. Some people have very few symptoms, and symptoms can come and go from day to day. Having no nausea doesn't mean something is wrong. If symptoms stop suddenly and you're worried, or you have bleeding or pain, contact your midwife or doctor.
What are the warning signs in the first trimester?
Get urgent help for heavy bleeding, severe pain on one side of your lower tummy, shoulder tip pain, fainting or feeling very dizzy. Contact your provider promptly for any bleeding, if you can't keep fluids down, have a fever or burning when you pee.
How are first and second trimester symptoms different?
First trimester symptoms are driven by rising hormones: nausea, tiredness, sore breasts and peeing more. In the second trimester these often ease, and new ones such as backache, heartburn, skin changes and leg cramps can start as your bump grows.
Related guides
Track this in Momi
Momi is a free pregnancy tracker app for iPhone and Android that follows pregnancy week by week, estimates the due date, and keeps a pregnancy journal, weight log, kick counter and contraction timer in one place.
