hi there, congratulations on the imminent arrival of your baby:)
I would not recomend Mirena to you after just having a baby, particularly if you want to breast feed, as the chemical in Mirena is passed into your breast milk and therefore your baby will be getting a dose of mirena too. (and knowing what side effects it can cause in us adults, i would hate to think that a baby's delicate system is being subjected to that).
If you really want to try Mirena, then wait until you have stopped breastfeeding, and use NON hormonal methods of contraception in the meantime.
Also, with a new baby in the house, with all the joy that brings, there is also a lot of stress, with sleepless nights etc etc - Mirena can cause major
Depression in many people - it doesn't do that to everyone, but i would not want to take a chance on having a drug that can alter my emotional state, when i have a young baby to look after - you are going to need every bit of level headedness you can get, not have mirena turn you into a wailing banshee!!!
As Heater suggests, go look at the website of side effects - and i just see she has found another site specifically geared towards women who have recently given birth (see her new post above this one, on this page)- mirena is not recomended for anyone who has recently given birth, not only because of the breast milk being contaminated with it, but also because i guess the uterus is quite tender after a birth - and the Mirena, or any IUD can perforate your uterus and escape into your body cavity - this could mean that you cant have any more children as well as other major operations to get the damn thing out again.
There are many people who get on fine with mirena, but we on here have seen the other side of it, and it is not a pretty sight!! It is your body and your choice, but i would strongly suggest that you don't risk the health of your baby or your own long term health with mirena. Good luck with the birth and for your future, whatever you decide:) Let us know how you go:) x