I am a sixteen year old girl, and last night my boyfriend and I had sex. It was not the first time for both of us, and the last time we had sex was about a week ago. My period had arrived a day after we had sex last, and ended about two days ago. After intercourse, we noticed that I was bleeding and this morning when I woke up, I noticed that I was bleeding a little again. I am about 5'3 and at 128 pounds, and if this is necessary, his penis is about 7 inches long. I've been reading online that cervical cancer can be a cause, but I don't understand much about it. During my first time having intercourse, I did not bleed at all, nor did it hurt. Last night, nothing hurt (nothing hurts now either), and I didn't even notice that I was bleeding. Why do you think I started bleeding? I would also like to know if I will bleed everytime I have intercourse from now on.