Mirena IUD fall out?

Patient: I had the mirena coil inserted just under two years ago. Just under a month ago as I was flushing the toilet I thought noticed strings going down but couldn’t not fully see as it flushed away. I can not feel my strings anymore but my partner thinks he can feel them during intercourse. Yesterday I began my first period in about a year and a half. Could the coil have fallen out?

Doctor: