I had sex with guy a on may 26 2016 and i had sex with guy b on june 3 and 4 and my docter said my conception date is june 5-6 who would be the dad?

Too close to call: That's too close to call. One should keep men 2-3 weeks apart in order to be able to predict who the father is, because the weeks of pregnancy, the differences in each man's sperm, the survival time of sperm in a woman, the ovulation day, and the conception day, are all estimates. (A simple way used over many centuries is: the father of the baby is the man she is married to.)