Late period because of sex

My period wuz due on the 14 and didn't come till the 19 n I was worried ....well not really because my tubes r tide but I was wondering why and I think I figured out why it was late because I slept with this guy who is really huge then normal I think it knocked up my period you would think it would make it come down but then these cramps r killer like I'm dying I'm n so much pain it feels like I want to puke .....