Hi Dee46,
I too had a long bleed a couple of weeks after the Mirena was fitted. It lasted for about 10 days or so, for me it wasn't very heavy, I used pads as advised by the Dr who put it in, and then it stopped.
The Mirena can take a while to settle down, for me I only had that one long bleed and after that I had more of a dark old blood appear about the time of a period, and no real bleeding again. Although I did have a show of bright red fresh blood once, about a year after it was fitted, which did freak me out after having no proper bleeding for so long.
Although for me my periods had become much heavier, compared to some other women I suspect they weren't that heavy, so that might be why I've had no real bleeding since it was put in. Had Mirena 2 years now.
I didn't start HRT (25mg patch) until 4 months after the Mirena was fitted.
Patch now a 75mg one. Periods more a slight beige smudge on a panty liner now and now about 7-9 weeks apart and not the 28 days or so before. Been peri for 8 years, so hoping ovaries are shutting down more now.
A few other ladies may have some advice for you soon, but the Mirena does seem to be tricky to predict how it effects each woman. That much I've come to realise.
X