Thanks for your time and effort by the way.
you're right, my period started on that same day too, just few hours after the intercourse. *sigh! i hope it's my boyfriend's. by the way, my boyfriend is 62 years old already and i'm 32, do you think that would change your analysis?
For my clarification, you had intercourse with the other man on Dec. 21 and that same day/night you started your period? If that's the case, ovulation wouldn't have occurred, thus fertilization wouldn't have occurred with the other man. Based on your cycle start date of Dec. 21, you very well could've ovulated as early as Jan. 2. But another thing to consider is sperm can survive within a woman's uterus for up to five days. So it's very possible that your egg was fertilized while he was off to his business trip. I sincerely believe your boyfriend is the father. Hope this helps.