First trimester guide: what happens and what to expect in the first 13 weeks

The first trimester runs from the start of pregnancy to the end of week 13. Not much shows on the outside, yet a great deal is happening within. This guide explains what you can expect, calmly and clearly.

How does your baby develop at this stage?

Because pregnancy weeks are counted from the first day of your last period, the first two weeks actually come before conception. After fertilisation, a small cluster of cells settles into the womb and the embryo begins to take shape.

• Around weeks 5–6, the basic structures for the heart and nervous system form.
• Towards week 8, limb buds and facial features become clearer.
• From week 10, your baby is called a fetus; most organs have taken their basic form.
• By weeks 12–13, fingers separate and your baby makes tiny movements. You will not feel them yet.

So these three months are a very fast period in which the foundations of the organs are laid. That busy work shows in your body too.

Common symptoms

Symptoms vary a lot from person to person. They may be strong or mild, and both are within the usual range.

• Tiredness: Hormone changes and a growing blood volume leave many people sleepy during the day.
• Nausea and vomiting: Often called morning sickness, it can strike at any hour. It usually eases around weeks 12–16.
• Breast tenderness and fullness.
• Needing to pass urine more often.
• Sensitivity to smells, cravings or aversions to certain foods.
• Mild groin twinges and mood swings.

Having no symptoms at all is not a reason to worry either; every pregnancy has its own rhythm.

First check-up and tests

According to the Turkish Ministry of Health guideline, the first antenatal visit takes place within the first 14 weeks. Your history is taken, you are examined, blood and urine tests are requested and screening tests are explained. An early ultrasound (usually weeks 6–10) can confirm that the pregnancy is in the womb and show the heartbeat and gestational age. Between weeks 11 and 14, the nuchal translucency (NT) scan and combined test come up. This is not a diagnosis but an estimate of chance, and you go through the results with your doctor.

What can you do?

• Ask your doctor or midwife about folic acid and other vitamins; they will advise on the product and dose.
• If you feel sick, eat small amounts often, try a dry snack before getting up, and sip fluids slowly.
• Avoid smoking and alcohol; if stopping is hard, asking for support is a sensible step.
• Avoid risky foods such as raw meat and unpasteurised dairy. If you are unsure about a food, you can check the Can I eat it? feature in the app.
• Sleep regularly and take gentle walks. Unless your doctor says otherwise, light exercise is generally safe.
• If you take regular medication, do not stop it or start a new one on your own; speak with your doctor first.
• There is no rush to share the news. When and with whom is entirely your decision.

When to contact your doctor

• Bleeding that soaks a pad, bleeding with clots, or severe cramping pain
• Sharp pain on one side of the belly, pain spreading to the shoulder, dizziness or a feeling of fainting (in this case call 112)
• Vomiting so constant that you cannot keep fluids down, or marked weight loss
• Fever, or burning when passing urine
• Intense worry or low mood that lasts through the day

Light spotting is often harmless, but it is still good to let your doctor know.

Feelings are part of it too

Joy, worry and uncertainty can sit side by side in the same day. This is very common. Give yourself time, talk to someone you trust, and ask for help when you need it.

This article is for information only; your doctor's or midwife's advice for your own situation comes first.