What does it mean when you have a period twice the second one being extremely heavy bleeding and cramping really bad?

Heavy bleeding: It can be a variety of things including fibriods, endometriosis, dysfunctional uterine bleeding, or even pelvic inflammatory disease. Usually your doc will take a complete history, do a pelvic exam, and will consider an ultrasound. Treatment, like most things, depends on the cause of the painful, heavy periods. Majority of the time, a pregnancy test is the first step. Best of luck.