I had unprotected sex with someone on December 31st, got my period January 13th (very normal, lasted the usual amount of days). I recently got back with my boyfriend and we had unprotected sex January 31st (actually we always have unprotected sex but I know for sure that he did not pull out that time) I am now pregnant and want to know if there is a possibility that it is from December 31st??
Please help!