I had severe cramping and heavy bleeding on and off during the first three months. Since last August I went from 136 to 144 without changes in my diet or exercise.
I'm getting mine taken out on the 23rd. I've been doing some research on the hormone in Mirena, I found a gov website that says the following: "Levonorgestrel should not be used to prevent pregnancy on a regular basis. This medication is to be used as an emergency contraceptive or backup in case regular birth control fails or is used incorrectly."
I also researched the side effects:
All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome when using Levonorgestrel/Ethinyl Estradiol:
Acne; breast tenderness or enlargement; changes in appetite; changes in weight; dizziness; headache; loss of scalp hair; nausea; nervousness; stomach cramps or bloating; vaginal spotting or breakthrough bleeding; vomiting.
I'm just done with mine.