yeah, that would have shown up in your bloodwork by then...i'm sorry man.
No , The last time i had sex with a different person was the month of aug the year before with a previous gf of three month somewhat 7 month ago. Now if this had come from this relationhip with no simptoms at all!! would or would it not show up in my blood work?
Honest Opinion: Have you had sex with anyone esle in the March time period? If no, and everything you say here is totally accurate, then it would suggest that she did. If you had sex with anyone else near that time (Dec,Jan,Feb,Mar), then it could have been either of you.