M.T.
I had got my Mirena IUD after my second child. I did not breastfeed her for long, so I can't directly answer your question. However, after reading the other responses it sounds like you will not have problems. Talk to your doctor about it and see what he/she says. Your doctor should have the statistics on this. I hope you are able to get this wonderful form of birth control! I have had mine for almost 4 years now and LOVE it. It is wonderful to not have to worry about taking my birth control...plus it stopped my period. Two things not to worry about!!!!!!