K.W.
I would first recommend calling your DR and asking about it just to be safe but if you aren't having very painful cramping I wouldn't worry about it to much. I had my Mirena placed 6 weeks after having my son and i bled for about one and a half weeks or so. (But i don't know if it was because of having a baby or because of the Mirena). I have now had it in about 2 years and no problems at all I luv it. Good Luck!