Stupid question? Maybe

So I had unprotected sex with my bf the 6 of sept that day it was also my ovulation day ... he finished in me . Close to two weeks later I started to pee a lot .. we had a mind that I could end up being pregnant . My period was suppose to come around the 20th . I read someone where that it takes two weeks to conceive so would that mean I would be 3 weeks ? ( FYI I am pregnant I just want to know how many weeks I am 😅😅 i have no clue ) or do I count from the day of my missed period which would be a week ?