My dr told me they do not add 2 weeks on the dating ultrasound. what does that mean?

Dates: a pregnancy id 40 weeks from the first day of the last period. if your ultrasound gives the exact fetal age it is 2 weeks less than the age by dates. So if you are 8 weeks pregnant the US in that case would say 6 weeks. Some give the figure by dates some by fetal age ask which.

2 wks. added already: If the doctor says not to add 2 weeks to the number estimated by the ultrasound, that means the number already includes the 2 weeks. That means the number is the "number of week pregnant" the woman is, on the day of her ultrasound. (if the number did not already have the 2 weeks added on, then the number would be the "age of the fetus", which is 2 weeks less than the "number of weeks pregnant")