Some women get a positive, I got faint positives a blood test is the best way to tell. And mine was still in place but I still conceived.
I had the mirena and after a while I stopped having periods. However I have heard of cases where people get pregnant with it and it can be very dangerous. I believe if u are pregnant it would show up on a test. I would definitely get an appt with your Dr just to make sure everything is ok
I dont have the Mirena but my sil does and has had hers for almost 5yrs. She hasnt had a period for at least 3 1/2..... Its definately weird not having a period but nice at the same time I guess. As long as you've checked the strings to verify its still there its probly just the hormones stopping your cycle. I think its pretty common but check with your ob if your worried, : ) hope this helps