My daughter had severe pain all thru her midsection during her period for several years, and heavy bleeding. They did ultrasounds and ct scans and offered tentative diagnoses, but didn't really know what was going on. She took high powered pain meds for a few years for it. She was 28 and had 4 kids so Dr offered her a hysterectomy. She had it done, and they discovered after removing her uterus that the problem was an enlarged uterus. (Basically the uterus doesn't "empty" everything each month and it builds up over time. Hers was 4 times the normal weight.) You might have your Dr check for this condition. There is also endometriosis, and other conditions that can cause pain. I hope it gets better soon.