When to worry?
I have had Mirena for 4 months and i recently started cramping after my period and i am still spotting a week later. My OB never really told what to watch for or to worry about.
I would contact your OB to see if it's something to be concerned about. I've never had an IUD but hopefully some of the mommas who have on here can chime in on if this is normal or not.
I just got mine about 3 weeks ago. They told me that the first six months you normally get more cramping and spotting between periods and that your periods can be more painful or heavy the first six months. Then all of that should be decreasing. If it is not sharp painful cramping I wouldn't worry too much but if it is I would call the doctor. The mirena website has great info on there about what to expect the first six months. The doctor that did mine gave me a lot of information too. It is very different from birth control pills that's for sure!
I would check to make sure you can still feel the strings and if so then you should be fine.
Oh yuck! They must have cut them too short. If it was in place a month after you should be good though. I always go to planned parenthood for my birth control because I figured that that is what they do daily.