I only had sex christmas weekend out of the whole month. I made the worst mistake of sleeping with my ex 24 hours after I had sex with my current boyfriend (who I think is my son's dad). i saw my ex on the 27th of December, a Sunday. Wouldn't I have a different due date if he was the father?  Out of all of our two years together he never got me pregnant and tried so hard! It would be so funny if he just so happened to complete his mission that last time. We are waiting on test results but I'm so anxious.