I have had sex multiple times before this happened but when me and my boyfriend had sex I bled on him and it was about a week before my period, it stopped right after sex! It was bright red and not that much blood but now I'm not getting my period, could that have been my period? It wasn't much blood though, but I have been stresse a lot recently and just started working out again a week ago or so, so could of that changed it?! Help!!