it could be our either pregnant or that your wall is building which could slow your period for the time being, i had my mirena for 2 years LOVED IT!, i had it removed because of ttc so best of luck
I just saw my obgyn last week and she suggested mirena for me. She said it thins out the uterine lining with hormones and that it can take awhile to build back up after using it, so a lot of women have no periods during and after use for a few months. Hope that helps a little.