I have a period tracker on my phone. According to that my fertile days were the 17th-21st and the 23rd-27th, and my ovulation day was the 22nd. I'm on Nuva ring but I had tried the 4 week method where you leave it in and go directly to a new ring without a period. That didn't work well and I had breakthrough bleeding every single day for 3 weeks. So I took the ring out 3-4 days ahead of time and gave my body a week and a half to 'reset'. I put the new ring in on the 19th, but my bf got a little carried away on the 18th. Seeing as how the ring had been out for a week and a half and the new one probably took another 7 days to be fully effective, I don't think I was protected at that point.