BAD CRAMPS!!

Hello everyone. 
I've had my period for almost a year now. -16 right now.. I have always experienced minimum to no cramps during my period. 
Then about an hour ago, I started experiencing the worst pain ever!!! Ugh it hurts so badly. 
I don't know what I did wrong...I was exercising till I felt really terrible!  I've never had this much period cramping in my life!!
Please help!!