I should know the length of pregnancy / number of weeks I am pregnant


There are different ways to find out the length of the pregnancy: 2

  • A woman can count the number of days that have passed since the first day of the woman’s last menstrual period (LMP). Many women make a note of the first day of each menstrual period on a calendar so that they can check it if needed
  • A woman can have a physical exam done by a nurse, midwife or doctor. An experienced professional will be able to assess the duration of pregnancy through a pelvic examination starting from around six weeks since the first day of her last menstruation.
  • A woman can have an ultrasound. This is especially recommended if :

- The woman isn’t sure of the first day of her last menstrual period and a physical exam is also inconclusive, or

- The woman has become pregnant without resuming her period after an abortion or childbirth.

Additional information:

Pregnancies are conventionally dated in weeks, starting from the first day of the last menstrual period and not dated from the fertilization as some people might think. 18 If a woman has a regular cycle, ovulation usually occurs about 2 weeks after a woman's menstrual period starts, and fertilization usually occurs shortly after ovulation. Consequently, the pregnancy length is about 2 weeks more than the weeks passed since fertilization (the date you had sex). If you are calculating the pregnancy length based on the probable date of when you had sex and became pregnant you should add up about 2 weeks to get the approximate pregnancy length.