My cycles are very regular I had a period on 09/ 01/ 2008.. and I had sex on 09/27/2008 and my period came on regular 10/01/2008.. now I had sex again 10/10/2008 I am pregnant now when did I conceive

My guess would be the 10/10/2008 date. Your doctor would be able to estimate that by the growth of the fetus. Has your doctor given you an estimated due date?

Some women can menstrate through their pregnancy. Fetus growth, like nikosmom said, can determine that for you.

***moved from Adult Sexuality because this is CLEARLY about pregnancy, not sexuality***

I'd say you concived 10/10/08... that sounds about right.