I had the mirena fitted around a week ago. And have started experiencing some heavier bleeding and cramps. I know it says you can experience some bleeding/spotting after but I just didn't expect so much its period like. The first day of fitting I had painful cramps then after that it was fine apart from some light spotting for the last 5 or 6 days or so. Then last night lots of blood and now cramps and bloods. Is this normal. How long should I expect all this bleeding to last?