Levonorgestrel
"Insertion was quite painful. Cramping, although no bleeding. 

No period at all for the first 6 months. My first period was about 5 days long & very light. 

But I gained 5 lbs since I got it. Food cravings are ridiculous and I recently developed an unbearable odor coming from my cervix. 

Monthly, I'm supposed to check the string to make sure mirena is still in place, and doing so after my first period, there was a thick white discharge that smelled sour and wouldn't go away even after douching daily. I got myself checked for an infection because it was accompanied by itching when it first started (no multiple partners)  I thought it was a yeast infection, but I was clear; no infection at all. I think the bad outweighs the good for mirena."