How Do I Know What My Date Of Conception Was?

Exact date of conception is difficult to know because it depends upon ovulation. Usually ovulation occurs at mid of the cycle but in some ladies it can be early or late. Sperms after ejaculation during sex can stay alive with fertilizing ability for 3-4 days. So, when you ovulated and conceived can not be calculated exactly. That is why pregnancy is calculated from the first day of the last periods. Hypothetically, date of conception is calculated by adding two weeks in the first day of last periods.