Pregnancy test said 2-3 weeks preg.......when did i get pregnant then /would of had sex 2/3 weeks ago? confused n how itworks.

Not exact timing: A woman usually ovulates about 14 weeks before the period, or about halfway through the cycle. Sex a day or two before the ovulation has best chance of inducing pregnancy. So if you know the first date of your last period, add about 14 days to that and that was the day egg was fertilized. It takes the egg about 10 days to get implanted. There are variations so it is hard to give exact date.