5 weeks pregnant: the heart starts to beat
The week many people realise they are pregnant. Your baby's brain, spine and heart are taking shape, and your body is starting to tell you.
Updated October 13, 2026 · sources checked October 13, 2026
In short
At 5 weeks you are in the first trimester and many people realise they are pregnant now. The NHS says the brain and spinal cord are forming and the tiny heart will beat for the first time around now. The one thing to do this week: keep up folic acid, avoid alcohol, and contact a midwife, GP or OB-GYN if you have not yet.
Where you are at 5 weeks
You are in the first trimester and, by Cleveland Clinic's grouping, at the start of month two (weeks 5 to 8). Your period is probably late. The NHS notes that home tests are sensitive from week 3 or 4 onwards, so if you have been waiting to test, now is a good time. Not everyone has regular cycles, so do not worry if you are unsure of your dates: the pregnancy week calculator gives a first estimate, and your dating scan will refine it.
Your baby this week
The NHS gives a length of around 2 mm and compares the embryo to a sesame seed.
- The neural tube, which becomes the brain and spinal cord, is forming (NHS, Cleveland Clinic).
- The heart is starting to form and beats for the first time around now (NHS). Cleveland Clinic says the tiny heart tube pulses about 110 times a minute by the end of week 5.
- The face is beginning to take shape, and the first blood vessels that will make up the umbilical cord are appearing.
- The placenta is being created, ready to bring nutrients and oxygen.
Your body and common symptoms
Extreme tiredness is one of the most common feelings now, the NHS says. You may also notice sore breasts, nausea at any time of day, mood swings, a heightened sense of smell, needing to pee more often and a milky white discharge.
Some light bleeding around now can be implantation bleeding, when the embryo attaches to the womb lining, and it is easy to mistake for a period. Mention it anyway.
Cravings. Some people get them, some do not. Eat as balanced a diet as you can manage. If you crave things that are not food, such as dirt, tell your midwife or doctor: the NHS says this can be a condition called pica, linked to low iron.
Worry is normal too. The NHS says around 1 in 5 mums feel anxious or stressed during pregnancy. Talk to your midwife or doctor, and try slow breathing exercises when your mind races at night.
Is this normal? When to call
Tiredness, nausea and mild cramps: normal. Spotting: common, but always worth a call.
Contact your maternity unit, early pregnancy unit or GP (UK), or your OB-GYN or midwife (US), for any bleeding, or for pain low on one side of your tummy, shoulder-tip pain or discomfort when peeing or pooing, which the NHS lists as possible signs of an ectopic pregnancy. Call NHS 111 if you cannot reach anyone. Call 999 (UK) or 911 (US) if you are bleeding with severe tummy pain, shoulder pain, or you feel faint or dizzy.
A word about miscarriage
The NHS describes the main sign of miscarriage as vaginal bleeding, sometimes with cramping in the lower tummy, though bleeding has many other causes too. ACOG says early pregnancy loss happens in about 10 of 100 known pregnancies and is usually a random event that nothing you did caused. If you need someone to talk to, Miscarriage UK has a support line on 0303 003 6464, and in the US Share Pregnancy and Infant Loss Support offers free support.
Appointments and tests coming up
- UK: refer yourself to maternity services or tell your GP. Your booking appointment usually takes place between 8 and 12 weeks and lasts around an hour; you will be offered screening for infectious diseases and for conditions such as Down's syndrome (NHS).
- US: call an OB-GYN or midwife practice to book your first prenatal visit. Ask whether they want you to start prenatal vitamins straight away; Cleveland Clinic notes at least 400 micrograms of folic acid a day.
- Both: if you take regular medicine or have a long-term condition, ask for an earlier conversation.
Your week 5 checklist
For your partner
Learn the warning signs above with her, and be the one who makes the first call if she is too tired or anxious to.
Previous and next week
Week 4: a positive test · Week 6: limb buds and morning sickness · The first trimester · All weeks
Questions parents ask
What are the signs of an ectopic pregnancy at 5 weeks?
The NHS says symptoms, if any, tend to appear between weeks 4 and 12 and can include tummy pain low down on one side, vaginal bleeding or a brown watery discharge, pain in the tip of the shoulder and discomfort when peeing or pooing. Contact your GP or NHS 111, or your OB-GYN in the US. Call 999 or 911 for sudden intense pain with dizziness, fainting or looking very pale.
What should I avoid at 5 weeks pregnant?
The NHS advises stopping smoking and alcohol, going easy on caffeine, and not stopping any regular medicine without talking to your doctor. Food safety also matters from the start, so keep a list of foods to avoid to hand.
Is it normal to have cravings at 5 weeks?
Some people have them and some do not. The NHS says cravings come from hormone changes affecting taste and smell. Tell your midwife or doctor about unusual cravings such as wanting to eat dirt, which can be linked to low iron.
Sources
- NHS — Week-by-week guide: week 5 checked October 13, 2026
- Cleveland Clinic — Fetal development: week-by-week stages of pregnancy checked October 13, 2026
- NHS — Ectopic pregnancy checked October 13, 2026
- NHS — Miscarriage checked October 13, 2026
- ACOG — Early Pregnancy Loss checked October 13, 2026
Mamavela explains; it does not replace your midwife, doctor or pediatrician, who know your situation. If something worries you, call them. In an emergency, call 911 (US), 999 (UK) or 112.