I strongly recommend against the Mirena. I think you need to research about how it works in your body. It's job is to irritate the lining of the uterus. If you read the insert it recommends that the woman getting it have at least one baby. Why is this, you ask? Because it can cause permanent infertility!!! So, if you want more children, then I suggest you NOT get this. Sure, your doctor will probably tell you that the chance of this happening is low, but he's not the one getting it, you are. Please, do NOT get it.
I highly recommend you get a hold of a book called "Taking Charge of Your Fertility". It's empowering to be in control of your own fertility and not be managed by drugs, devices and doctors! Please do your research!
Are you aware that the "Pill" is the only drug manufactured to fix something that isn't broken??? Why would we put a drug in our body to stop it from working properly! Would you ever take a drug that made your heart or kidneys work differently than they're supposed too? NO Way!! So, why do we women do this with our uterus and ovaries?? It's not healthy.
I'm a nurse and have seen patients with blood clots and strokes from the pill, these are YOUNG patients, in their 20's. I've also seen women suffer from side effects of IUD.
From one woman to another, please empower yourself and learn about how your body works and control it yourself.
Good luck!