I have been taking norethisterone constantly with no breaks for over 2 years now and after having the Mirena fitted about 7 weeks ago, my consultant wanted me to continue taking it until my ultrasound. The ultrasound showed the Mirena to be in the right place and now he wants me to stop the norethisterone to allow the Mirena to take over. I took my last norethisterone on Sunday afternoon and was wondering how long it will be until the bleeding starts. My consultant pulled a face when he said that unfortunately I will bleed but hopefully it won't be too bad. I'm already experiencing a period style tummy ache but surely its too soon. Even though I'd been on the norethisterone for so long, within an hour of the Mirena being fitted I started bleeding and it lasted on and off for 4 days. I just wondered if anyone had any experience with this. Guess I'll have to start packing extra undies, pads and liners every time I leave the house again.