I had the Mirena inserted back in March (2009) and I had some problems the first 3 weeks of having it in, but everything seems fine now. My periods are regular, not heavy, they don't last a full week anymore, I got off the iron pills I had to take prior to the Mirena because I was bleeding bad, had softball sized clots, it was just awful. Now everything is so much better. Only thing I have is headaches during my periods when before it was severe cramping. I don't mind the headaches so much, one Tylenol and I'm good in 30 minutes. Every woman's body is different, some have bad effects from Mirena, others don't. And believe me, I had a bad time in my life with my body, and since I got used to the Mirena, everything changed for the better. I'm glad I got it.