The NuvaRing is a form of hormonal birth control. It is a thin plastic ring about the size of a silver dollar that is inserted into the vagina, similar to the way you insert a tampon. It releases estrogen and progestin over a three-week period, after which you remove the ring, wait seven days (this is when you will have your period) and then insert a new one.
The NuvaRing should be left in place during sexual intercourse. Used properly the NuvaRing is about 98 to 99 percent effective. The NuvaRing does not protect against sexually-transmitted diseases.