I got my first pp period in September. I had one in Oct and Nov as well. This month, all I've had is spotting...for two weeks! I love the protection Mirena provides, but I don't like the inconsistency it gives with periods. I did take a pregnancy test a week ago to be sure that wasn't it, and it was negative.
I'm hoping DH lets me take it out in January to TTC. We've been talking about it anyway, but I told him to wait till Christmas to tell me.
Re: Annoyed with Mirena..
If you can, stick with it the first 6 mos were like that for me. After 6 mos, spotting for a day or 2 per month. By a year no period!!!