Nuvaring Mistake

hi everyone, I made a mistake and left my nuvaring in for 4 weeks which I thought would be ok because I was just skipping my period. I'm now reading that you're actually supposed to replace the ring on the first day on the fourth week instead of leaving the old one in for four weeks. I know that if I removed the ring for my period I still would have been protected for this fourth week, so is was I still ok even though I didn't remove it? should I just put the new ring in today? tyia.