Mirena help wanted!

I saw a doctor yesterday re: Mirena. I have never had a baby, but I am interested in getting off the pill just to see what normal feels like. He's willing to insert the Mirena, which sounded great, but then I started reading all these messages about bloating, depression, cramping and constant bleeding the first few months, and I just don't know if I have the stomach for it. My goal is to feel normal again. Is Mirena much different (aside from the light periods after a few months) from not being on anything emotion-wise? (I've considered going to condoms, but I'm going to be in law school, so my husband and I really can't afford a baby in the next three years.)