Who is the father? Please Help Me

Patient: My first day of my last period was March 24th 2011 am on a 28 day cycle. from what i understand my ovulation was the 1st of april to the 6ths. i had sex with Guy A during said ovulation and Guy B on the 7th is there anyway that Guy A is the farther?

Doctor: Your ovulation date would normally be 14 days before the start of your next period. Thus your ovulation date is most lik ely Apr 7, 2011, which means you are likely to be fertile between 5th and 10th of April 2011. If you had sex with Guy A between 1st and 6th of April, that would be before you may have ovulated, but since sperms live up to 4 to 5 days once inside you, there are chances that he might be the father. But more chances are that the Guy B is the father. However chances of Guy A being the father cannot be ruled out.