I've had my Mirena IUD for 2 years now (put in 2/2018). Starting in May of 2019 I got my regular cycle back, it's just lighter. Apparently Mirena only prevents ovulation in about 40% of women. I know I'm ovulating because I've tracked my cm and taken ovulation tests. I've now had positive frer test two months in a row on CD 9/10, then negative after that. Is it possible that I'm getting pregnant, but the IUD is preventing the fertilized egg from fully implanting? I have an appointment this week to talk to my doctor about this. Just wondering if anyone else has experienced it.