This is my 2nd period in less then 3weeks what could be wrong?

Vaginal bleeding: Vaginal bleeding like this 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 bleeding. A pregnancy test is the first step. Best of luck.