Levonorgestrel
"Follow up:  so it's been 1 month and I have had some bleeding everyday single day.   My first period after insertion was much heavier and I had cramps (one particular tough day) but spotting ever since.   I was a little worried  if the Mirena is in the correct position and the gynaecologist says every thing appears fine and my lining is thinning correctly and that I should notice the spotting will come less frequently so I'm going to stick with it and hope that everything  goes as she says it will.   I've had no weight gain but my skin had had some minor trouble but other than that and the spotting everyday I feel great and am happy with my decision."