🤰 5 Weeks Pregnant

You are in week 5 of your pregnancy — the first trimester, month 2. Your baby is about the size of a sesame seed. The neural tube, which becomes the brain and spinal cord, starts to form.

By the Power Calculators team Updated 5 Nov 2026

Baby is the size ofa sesame seed

TrimesterFirst

MonthMonth 2

Weeks to due date35

Your baby at 5 weeks

The neural tube, which becomes the brain and spinal cord, starts to form.
A tiny heart tube begins to develop.

Average length	0.2–0.3 cm
Size comparison	A sesame seed
Days completed	35 of 280 (13%)

Your body at 5 weeks

Tender breasts, tiredness and needing to wee more often are common early signs.

To do this week

Keep taking folic acid. Eat little and often if you feel queasy.

When to call your doctor

Vaginal bleeding or fluid leaking
Severe tummy pain or cramping
Fever over 38 °C
Severe headache, blurred vision or sudden swelling of face or hands
Vomiting so much you cannot keep fluids down

Pregnancy Due Date Calculator

Find your estimated due date, conception date and how far along you are, from the first day of your last period.

Pregnancy Week Calculator

Find exactly how many weeks and days pregnant you are today, your trimester and your due date.

When to Take a Pregnancy Test Calculator

Find the earliest day to take a pregnancy test and the most accurate day, from your last period and cycle length, with implantation dates and test accuracy by day.

Frequently asked questions

How many months is 5 weeks pregnant?

5 weeks is in month 2 of pregnancy as months are usually counted (about 1.1 calendar months since your last period), in the first trimester.

How big is the baby at 5 weeks?

About the size of a sesame seed.

What should I do at 5 weeks pregnant?

Keep taking folic acid. Eat little and often if you feel queasy.