Just stopped nuvaring- pregnant already?

I have been on bc for 13 years and finally got off of it last month. I most recently was on nuvaring for about 5 years. I took the ring out, got a period, but now am about 6 days late. I have never been late before, but that of course is because I've been on some form of hormone for so long. I did take a pregnancy test and it was negative. Has anyone else stopped nuvaring and had irregular periods after? If so how long did it last?