insane Uterus and intestinal cramps

So I'm 16 and got my period when I was 12. I've never gotten cramps. I don't even experience any signs of an upcoming period besides sore tits. But yesterday when me and boyfriend were getting down, I started experience this major pain near my g-spot. I thought it was just swollen becuase you know I was aroused and it may have been pressing on my bladder. So I asked him to stop so I could try to pee. Nothing came out but I started experiencing pain that made me tense up. So far I'm 80% positive I have insane pre-period cramps and intestinal cramps. The intestinal cramps haven't stopped and my period isn't for another week... Should I get this checked out? I had to leave an important 7 hour sports practice becuase I couldn't participate with all the pain. It kept me up all night too. Someone please help me, I hope this doesn't affect having kids...