Dating pregnancy irregular periods

Use our Pregnancy Calculator to calculate these dates for you.If the mother has a regular period and knows the first day of her last menstrual period, gestational age can be calculated from this date.

However, estimating your conception date may be useful when trying to determine your due date or even simply to assess your baby's growth at this stage in your pregnancy.

There are several ways you can make an educated guess.

Your baby will spend around 38 weeks inside your uterus.

Though the average length of pregnancy is always calculated at 40 weeks. The reason is because your pregnancy is counted as having begun from the first day of your last period and not the actual conception date (usually around two weeks later).

The method requires you to know the first day of your last period (LMP).