I have been on the nuva ring for years first time ever i started spotting brownish red sunday took ring out monday and still spotting. why is this?

Breakthrough bleed: Sounds like breakthrough bleeding which occurs when you have bleeding at unscheduled times. Brown is simply old blood that has been sitting at the back of the vagina. Often things get back to normal the next cycle. If not then schedule a visit to discuss changing brands or changing birth control methods. This is very common. Other than being annoying it is not dangerous.