Hi I'm taking contrapetive pill last 3months my period has been coming same time but this time pain in belly n clotting every time I wipe browish blac?

Not unexpected. Oral contraceptive pills work by inhibiting ovulation. One's menstrual cycle is often altered with a non-ovulatory cycle. Blood may not flow as well, stagnates, and becomes brown. Clotting may also result. I'm not sure why you might be having pain; more menstrual cramps would not be expected. Watch this, and if they persist or you have further questions, contact your doctor. Good wishes:)
See gynecologist. Menstrual associated pain not relieved by OTC meds needs to be evaluated. You could have endometriosis, ovarian cysts or even a STD.