please help??????????

So long story short, i had unprotected sex over 12 times. Even when I was ovolating. He came in me every time. I took a pregnancy test 5 days before my missed period and it came back negative. I don't start my period till the 11th. Today, I went to the bathroom and nothing was on my underwear. I wiped and there was very faint blood. I wiped again, and it was very faint blood. It wasn't nothing like period blood. I'm not cramping.