Ok, so i was supposed to start my period on Thurs Aug 21. I had some minor cramping the day before, but nothing like usual (they are usually really bad). The cramping stopped and didnt feel like i was ever going to start. Saturday Aug 23 my bf and i had sex and there was some blood on his penis so i put a tampon in. When i woke up i went to take it out and there was just a tiny spot of blood. I wore a pantyliner all day Sunday Aug 25 and nothing, once when i wiped there was a pink tint on the toilet paper....what could this be?