Hey T.,
I'm with Amber.....GET THE MIRENA!! I absolutely love it! I was a little weary of it after reading some horror stories on the internet. My doctor said that when women have problems with it, it's because their doctors have placed it incorrectly. I decided to just try it, and when my son was 8 weeks old I had it put in. I could definitely feel it at first (slightly uncomfortable). And there was a constant spotting (for me) for the first 2 months or so. I stuck it out and I am so happy I did. You don't ever have to think about birth control! And now, periods are few and far between and VERY light. I only got the 5 year one, but you can also get the 10 year, and you can have it removed at any time if you decide you want another baby. It's low-dose, so it shouldn't cause any weight gain. I really recommend Mirena, but do your research and find out what's best for you and your family.
Wish you all the best - God bless you!
J.