At week 5 almost nothing shows on the outside, but inside a great deal is being set up for the first time.
Your baby this week
- Heart
- A simple tube that will become the heart is forming, and may begin to beat around now.
- Brain and spine
- The neural tube, which becomes the brain and spinal cord, is closing up.
- Shape
- Your baby is a tiny curved embryo, a few millimetres long.
What you might notice
- Nausea, which can start any time of day, despite the name morning sickness.
- Needing to pee more often as hormones and blood flow change.
- A stronger sense of smell, and foods you suddenly can't face.
- Mood swings, from hormones, tiredness, and the news itself.
Call your midwife, doctor or early pregnancy unit today if
- You have bleeding, or cramping pain low in your belly
- You have sharp pain on one side, pain in the tip of your shoulder, or you feel faint
- You're being sick so often you can't keep fluids down
- You have a fever, or it burns or stings when you pee
If the pain is severe or you feel faint, call emergency services.
Coming up
Your first appointment is usually booked around here. What happens at each visit.
If you're on regular medication, don't stop it on your own. Ask first.
Questions to bring to your next appointment
- Is there anything in my health history that changes how my care should be planned?
- What can I take for nausea if it gets bad?
- Who do I call if I have bleeding or pain before my first appointment?
For your partner
Smells and tastes can change overnight. If your partner suddenly can't stand the coffee or the fridge, it isn't personal. Ask what helps and adjust.
NUGA follows you week by week
Enter your due date once and NUGA knows you're at week 5. The day before each appointment, it gathers what you've noted and the questions to bring.
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This page draws on public guidance from:
General information, not medical advice. Every pregnancy is different, and your midwife or doctor knows yours. Last updated October 2026.