How many weeks pregnant?

Yes they will always ask when's your last menstrual period is. If you have a very regular menses then it's easy to calculate but if you don't then it's difficult to know unless you do a scan which is more reliable. I have quite a regular menses and based on my last period, I was 11 weeks going to 12 weeks pregnant. But when I did my 1st ultrasound, I was only 10 weeks+ pregnant.

Hi it's calculated based on the first day or your last menses. However, usually the doctor will do a dating scan to confirm the gestational age. The doctor will take some measurements of the baby's tummy, thigh and head to give you a better gauge of the fetus' age. :)

Based on first day of your last period

base on last menses

yeap