If my conception date is april 15 does that mean i had sex around that date or could i have actually did it weeks before and that date was the outcome?

Conception date: This is a calculated time at which the fertilized ovum implanted into the uterine wall. It is unlikely that you conceived weeks prior to that, but anything is possible and dates of conception can be calculated wrong based upon misinformation. Estimates use last period, prob date of ovulation based on an average 28 day cycle, and time of sexual congress..