Is it normal to experience spotting then bleeding during last days of NuvaRing cycle?

Yes. Some women note that bleeding starts later in the ring-free interval than it did in the pill-free week if they were on the Birth Control pill. Other women note that bleeding starts a little before they remove the ring. If you're in the first three months of use, you may have more unscheduled and unexpected bleeding, and should then settle down into a pattern. If the bleeding is troublesome, occurs mostly during sex, or is accompanied by pain, discharge or fever, then contact your health care provider for advice.