I have had the mirena iud (plastic) for a little over 8 months, the first month I missed a period then it returned the second month and so on, every month it has been on the 29th when I start my period... I didn't have a period in December but the 29th of January I spotted only on tissue when I wipe.... It's now Feb 2nd and still no period, I was in the shower washing down there and it was a string of blood, is that normal on the mirena? Please help me!