Is it likely that i conceived a few days before my cycle since i had unprotected sex may 1-5 and had a normal cycle on may 13th. i'm 6 weeks and 2 day?

How it works: No. If you had a regular period after sex that represents not being pregnant. If you have not had an ultrasound yet to confirm your dates then you cannot in any way say when you conceived. Here is a good guide to use, but I would recommend that you base your dates upon the ultrasound when you have one at the OBs: http://www.babymed.com/conception-calculator.