I've used nuvaring for over 1 year, but this month after insertion my period did not stop. It's been 2 weeks today. Should I be worried?

Don't worry, no good ever comes from worry. What you describe is unusual. Your options include: taking out the current Nuvaring and immediately replacing it with another ring; taking out the current Nuvaring, and allowing your body to readjust, then restarting use of the Nuvaring after your next normal period, or seeing the physician who prescribed the Nuvaring to evaluate why this is occurring.