My Fiancé cheated on me with one of my family members!! I was so angry and tried to get revenge back by sleeping with my exboyfriend on Valentines Day wich was a one time only thing on 2/14/08. After that I then had my period which started on 2/19/08 which was regular. Since then I haven't sleep with him. I thought I was pregnant already but when I went to the doctor in the beginning of march to take a blood pregnancy test it came up negative. I recently found out I was pregnant that following April and the doctors told me I've gotten pregnant in the beginning of March and since the that of the incident in February I haven't had sex with no one other than my fiancé in March!! Please help me figure out if its my fiancé child or my exboyfriend.? :confused:

Odds are it is your fiance's... you had sex with your ex right before your period (probably the least likely times to get pregnant), you had your period on time, the first blood test came up negative, and your doctor feels you likely conceived early March.
If nothing else, remember that revenge sex gets you no where and can ruin a relationship even more. Good luck!