I don't know that i'd freak out over it... I've never used nuvaring, but I do know that most of the time hormones can make women experience spotting. Of course, I think it's mostly at the onset of starting birth control that people experience it, so it does seem kind of weird it would start a year afterwards.

My general principle is this: call your gynecologist! ;) I call mine early and often. In fact, they probably have a phone-book sized file on all the phone calls i've made since starting birth control pills in may! Mine doesn't charge for phone consultations, so if I have a question, I simply call the office and a nurse replies within an hour or so.

Best I can offer.
-rachel