What pregnancy week 5 means
The heart begins to form. “5 weeks pregnant” means 5 weeks have passed since the first day of the last menstrual period — the standard way pregnancy is dated. Conception usually happened about two weeks after that date, so the baby’s own age (fetal age) is roughly 3 weeks. Week 5 runs from 5 weeks 0 days to 5 weeks 6 days; on the following day the pregnancy is 6 weeks.
Your baby at 5 weeks
The neural tube — the structure that becomes the brain and spinal cord — is forming and starting to close. A simple tube-shaped heart is developing, and the first blood vessels are taking shape. This is the start of the embryonic period, when all the major organs begin.
A common way to picture it: the baby is now about the size of a sesame seed — roughly about 2 mm. These are averages; babies grow at different rates, and ultrasound measurements vary.
Your body at 5 weeks
Many people find out they are pregnant this week. Early symptoms often become more noticeable: tiredness, breast tenderness, needing to urinate more often and, for some, the first waves of nausea. Feeling very few symptoms is also normal.
Care and appointments around week 5
Your provider may book your first visit for a few weeks from now. It can help to write down the first day of your last period and any medicines you take, as both come up at the first appointment.
The timing of tests and appointments differs between countries and care providers. If anything worries you — such as bleeding, severe pain, fluid leaking, fever — contact your midwife, doctor or maternity unit straight away rather than waiting for your next appointment.
Week 5 in your pregnancy timeline
Week 5 is in the first trimester (weeks 1–13) and in pregnancy month 2, which covers roughly weeks 5–8. The second trimester begins in 9 weeks.
| Pregnancy start (first day of last period) | |
|---|---|
| Estimated conception | |
| Second trimester begins (14 weeks) | |
| Third trimester begins (28 weeks) | |
| Full term (39 weeks) | |
| Estimated due date (40 weeks) |
Dates assume you are exactly 5 weeks 0 days today. For dates based on your own last period, use the calculator above or the main Pregnancy Calculator.
5 weeks pregnant in days and months
5 weeks is 35 days of pregnancy — 13% of a 40-week pregnancy. Counted in calendar months, 5 weeks is about 1.1 months, which is usually described as month 2 of pregnancy. Months are only a rough grouping; healthcare professionals almost always talk in weeks and days because they are more precise. See Pregnancy Month Calculator for how weeks map to months.