I was worried about having a Mirena coil, having previously had Utrogestan. The Utrogestan never really controlled my uterine polyps and hyperplasia so I was told I would have to have a Mirena. I have found it suits me quite well. The bleeding seems to be easing up and the only side effect I have had is a bit of water retention, slowing down my digestive system. No aching breasts, headaches, mood swings, etc.
Have been pleasantly surprised. I wish i'd had it inserted years ago, when my perimenopausal periods were gruesome.