Dealing with Heavy and Painful Periods: Seeking Advice

I've had heavy, painful periods ever since my first one, sometimes highly irregular, and always involving severe cramping, muscle pain, joint pain, diarrhea, nausea, and headaches. Once I started birth control most of those symptoms went away until recently, with the recurring sharp pain and the irregular periods/spotting, as well as chronic headaches. Does anyone have any insight into what I should ask my doctor about? We've already done STI testing (lmao) and a pelvic ultrasound/transvaginal exam, we're just waiting for the results.