Hi, It is very much normal to have brown or pink vaginal discharge after starting birth control pills. It is due to hormonal imbalance caused by the birth control pills and body not being used to it. It is very much normal and subside itself with time-- usually within 3 months. Contraceptive pills act by making the inner lining of uterus thin and fragile and some of these lining are discharged in the vaginal fluid. Also, these discharged lining entrap some of the blood vessels and cause some amount of bleeding, therefore this blood and discharged lining mix with vaginal fluid and give the discharge brown or pink color. Some feeling of burning is due to a thick discharge caused by above changes and waiting for clearance from the body through vaginal route. Usually it clears itself by taking adequate liquids and staying well hydrated. More intake of liquids will result in more urine production; hence easy and early clearance of vaginal discharge. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Satnarain Bansal, General & Family Physician