The average pregnancy is 40 weeks long, as it is dated from the first day of your last period. So when many women take a pregnancy test around the first few days of their missed period, they are already around 4 weeks pregnant.
You can work out the date your baby will be born by entering the date of your last period in our Due Date Calculator below.
Keep in mind that this is just an approximate date as you won’t know exactly when in your cycle your egg was fertilised. Only 5% of babies are actually born on their predicted due date, most are actually born two weeks either side of the due date.