Due Date Calculator Conception So... I Know When I Concieved... My Due Date Makes My Conception Date A Week Later...?

So... I know when I concieved... my due date makes my conception date a week later...? - due date calculator conception

I told the doctor that day, from the first of my last term, like everyone else, and I was on 8 January or 08 "date. Well, I never asked if I knew that my time of conception, and always on the second day I was thinking in my maturity into an online calculator and said to his day of the show April 17 . I know, a fact which was 10 to 13 in April. It is from between five days to a week.
Does this mean that I have my baby before or after 37 weeks is just a guessing game, no matter what?