I'm on nuvaring birth control and the start of my last period was july 25th. on august 14th i experienced brown discharge and mild cramping. this has never happened to me before but i am sexually active. i was wondering what could have caused it?

Breakthrough bleed: Breakthrough bleeding (bleeding at the wrong time) is very common on birth control. It happens in about 1/3 of users. Its no big deal and usually self corrects over time. If you are not satisfied or it continues to happen then consider using a different birth control method. It is a common side effect and does not mean something is wrong or that the Nuvaring is not working.