Abnormal period?!?!??!

My bf and i are long distance. I took a week long trip to visit him, also a week before my period was due. I had a great time, of course we had sex. Unprotected, we used the legendary pull out method. (Verysmart of us lol). But anyway, I’m home now. My period was due on the 4th but didn’t come until very late that night. When it did come it was very light pink spotting with some cramps. It lasted only a couple of hours. I suffer from extremely bad cramps and heavy bleeding. My cramps make me vomit, very fatigue and pass out. I didn’t experience that this time and I’m worried. While having sex we always had to cut it short every time because it would start to hurt really bad. It was like that when he came to visit me in December. So now i have no bleeding but i still have the cramps. Could i be pregnant or did he throw off my period. I have no idea as to what is going on