28 weeks pregnant
This calculator finds an estimated due date and how far along you are. The worked example is a pregnancy at exactly 28 weeks.
How it works
Add 280 days to the first day of your last period to get the due date. To find the current week, count the days since that day and divide by 7. Here 28 weeks times 7 is 196 days.
Worked example
Say the first day of the last period is 1 April. The due date is 280 days later, on 6 January. After 196 days the date is 14 October. 196 divided by 7 is 28. That is the start of week 28. The 84 days left run to the due date. This example uses a 365-day year.
Common questions
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 6 January to 13 January.
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 1 April does not cross February. A leap year changes nothing for 6 January.
How many months is 28 weeks pregnant?
About 6.4 months. A pregnancy is 40 weeks, a little over 9 calendar months. Months are only a rough guide. At 28 weeks there are 84 days to the due date.
Which trimester is week 28?
Third 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 28 is week 1 of the third 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 26, which is 182 days.