I had Mirena fitted plus a biopsy in October due to post menopausal bleeding. I had period like bleeding for 5 weeks after. I was told it’s possible to have period like bleeding for up to 3 months or more while the Mirena settles. I’ve since had to have a replacement Mirena fitted in January due to the previous one having the threads cut too short, plus a hysteroscopy and a further biopsy as there apparently wasn’t enough viable tissue in the previous sample. Following that I bled for week then had light spotting around 4 weeks later, but nothing since.