What Is The Treatment For Irregular Periods And Painful Cramps?

I'm 18, erratic menstrual cycle. I'm Sexually Active. // My Period ended May 4th but i still have really painful cramps and i'm bloated, I've been super tired lately, i get headaches and my lower back and neck hurts. i don't have much of an appetite usually but i eat everything in my frigde once i get a hungry now. am i pregnant?