Hi so i got my period during sex? It was definetly time for me to get my period bcuz i was cramping and and my breasts were sore and painful like always before my period and while the intercourse we noticed blood on my boyfriends penis but then i only bled VERY lightly for that one night and it was completly gone by the next night. Is there anyway that the actual act of having sex can stop your period from flowing? i saw little brown discharge this morning but thats about it? i am very worried. just to add this : me and my boyfriend were both diagnosed with chlamydia a month ago and we both took the pills and went through the treatment.