I am on the pill and missed my period, had 2 negative pregnancy tests 2 days after missed period. cramping on 1 side, slight nausea and bloating?

Could be a cyst: Sometimes an ovarian cyst foms and causes these symptoms, even while taking the pill. It's important to see your doctor to find out what's going on. A transvaginal ultrasound exam can tell if you have a cyst.

Missed period : Reasons for missed/late periods: low body weight, obesity, marked weight ^ or v, over-exercise, endurance athletics, breast-feeding, ^ stress, illness, eating disorders (bulimia or anorexia), anovulatory cycle (no egg released), cyst, travel, hormone irregularities, drug use, meds (i.e., birth control) or medical problems. #1 reason is pregnancy.