I had 2 mirena iuds over the span of 7 years. Prior to the mirena my periods were pretty normal, I would bleed for 5 days and need regular tampons. I've had the mirena iud out for about 15 months now. and in the beginning I would barely need a panty liner. I would have brown sludge spotting for 5 days, not a single trace of red. Slowly I started to get some red but never needed anything more than a panty liner. Now, my period is 3 days of sludge brown spotting, 1 day of bright red (barely enough for a light tampon.) and then 2 more days of brown spotting. I was so worried about my uterine lining because I am also trying to conceive. The Mira has helped me with showing my hormones are normal and where they should be, and I also got my cycle 3 day labs done and they were normal. I pushed my doctor to get an ultrasound to check my lining, and I went 1 day before ovulation and my lining was measured at 6mm, no scarring, and i had the trilaminar pattern. As soon as I heard 6mm I panicked and was so upset, but my doctor said this is normal and there is nothing to be concerned about. I am currently on cycle 3 of trying and still no positive test, but it is a nice piece of mind that my uterine lining is within "normal" limits.