If you're pregnant, you want to know your baby's due date. Although only 5 percent of all women give birth on their predicted due date, knowing in advance can affect travel plans and other activities, in addition to being of interest to friends and family. This information can be calculated from the day of conception, although it is the date of the previous menstrual period that best determines the due date.
Step 1
Write down the date of conception.
Step 2
Determine the first day of your last period before conception. If you do not know when this was, you can estimate it by counting back sixteen days from the date of conception. This will only be a rough estimate, however, because conception typically occurs 11 to 21 days after the beginning of menstruation.
Step 3
Count ahead 40 weeks. This is your estimated due date.
Things You'll Need
- Calendar
