Mirena I had my Mirena put in about 3 weeks ago, I've had my period the entire time! No cramping and it's not too heavy, just annoying. I have also LOST 7 pounds in the last 3 weeks, I have been trying to loose weight-but I feel like the Mirena hasn't set me back from loosing the weight at all. No other side effects though! So far, I am very happy with it. I'm just really bummed about having my period for 3 weeks! My doctor said to give it 3 months to adjust and your periods will be better. Oh and I also feel like my sexual appetite has increased slightly-not enormously, but just significant enough to mention. I guess it does effect everyone differently!