So sex from december 28 could. have got me pregnant all so i did have sex with a 2nd guy but condom broke went to dr but every thing adding up to 2425?

Conception: Actually, sex from Dec 24 and Dec 28. Based on a LMP of 12/12 you ideally would have ovulated 12/26. However, in reality you could have ovulated any day between 12/24 and 12/28 that could have gotten you pregnant. Plus, there is a small likelihood that the Dec 19 intercourse got you pregnant.

Many possiblities: Any unprotected sexual intercourse can lead to pregnancy. Naegele's rule is a standard way of calculating the due date for a pregnancy, which may help. The rule estimates the expected date of delivery (EDD) by adding one year, subtracting three months, and adding seven days to the first day of your last menstrual period (LMP). Hope this will help.