What Causes Abdominal Cramps And Leg Pain During A Menstrual Period?

I have HORRIBLE cramps during that time of the month. I cant do anything but lay in bed and cry. It causes my back and legs to hurt, and i can not move. It makes me feel like im going to throw up and sick all around. I have 2 questions, is it possible i have an ovarian cyst? My mom had one when she was younger than me. and second, Ive had unprotected sex for about a year now, is it possible tha if i have a cyst that it is he reason i have not gotten pregnant?