If your period is regular and lasts 28 days, and if ovulation generally happens on day 14 of your cycle, then conception probably took place about two weeks after the LMP. For gestational age counting, these two weeks are added to a pregnancy as a simpler method than trying to track from ovulation or fertilization.

Do doctors add two weeks to conception date?

To account for the two weeks prior to conception, doctors take the first day of your last menstrual period (LMP) and add 280 days (or forty weeks) to determine the due date. From there, you can also determine how far along you are by counting how many weeks it has been since the first day of your last period.

Why do you count 2 weeks before conception?

Your weeks of pregnancy are dated from the first day of your last period. This means that in the first 2 weeks or so, you arent actually pregnant – your body is preparing for ovulation (releasing an egg from one of your ovaries) as usual.

How is conception date calculated?

Most women do not know the exact date of conception because it can be challenging to know exactly when ovulation occurs. Thus, their conception date is merely an estimate based on the first day of their last period.

How can I find out the exact date of conception?

The best way to determine your conception date is with a pregnancy confirmation ultrasound. Pregnancy ultrasounds look directly at the development of your growing baby to determine its age and when you likely conceived.

What does a fetus look like at 1 week?

Your baby weighs about 1/8 of an ounce — just bigger than a penny. The tadpole-like tail is almost gone, and in its place are two little legs. Your babys head is still huge compared to the body, but it will get more proportional in the weeks to come.