5 weeks pregnant
Week 5 of pregnancy means 35 days since the last period began. Use the form to place your own dates, or read the example below.
How it works
Forty weeks is 280 days. Add 280 days to the first day of your last period for the due date. Divide the days that have passed by 7 for weeks and days. Week 5 runs from day 35 to day 41 of the 280.
Worked example
Start at 16 May. Count 280 days ahead to reach 20 February. Count 35 days ahead to reach 20 June. 35 divided by 7 is 5 weeks. 245 days remain. A leap year shifts dates after February by one day.
Common questions
Which trimester is week 5?
First trimester. The first trimester covers weeks 1 to 13, the second covers weeks 14 to 27 and the third runs from week 28 to the birth. Week 5 is week 5 of the first trimester.
Why do weeks start from the last period and not conception?
Most people know the date of their last period but not the day of conception. Counting from the last period gives everyone the same starting point. A pregnancy is about two weeks longer on paper than from conception. Counted from conception, this would be week 3, which is 21 days.
How accurate is a due date?
Only a small share of babies arrive on the due date. Most arrive within a couple of weeks either side. Treat the date as the middle of a window. Here the due date is 20 February, and 245 days remain from week 5.
What if my cycle is not 28 days?
The 280 day rule assumes ovulation near day 14. If your cycle is much longer or shorter, your doctor may adjust the due date, often with an ultrasound. With a 35-day cycle some clinicians add 7 days, which would move 20 February to 27 February.
Does a leap year change the due date?
It can. A year with an extra day in February moves dates after that day by one. The calculator above uses the real calendar for your dates. The span from 16 May does not cross February. A leap year changes nothing for 20 February.