me and my fiance were sleeping together! im still a virgin and i think but im not sure that some semen passed through my underware! my period is supposed to be 31/december and  this happened at 26 december! my menstrual cycle didnt come till now and it comes every 28 days sharp! is there a probability after all this that im pregnant!?? and if im pregnant! is there a drug that could be taken to avoid this without losing my virginity! can pregnancy appear after the semen enters a vagina by 3 days only!!??