I had a big withdrawal bleed a few days after removing my mirena, this was not a period, as I’m still in peri and just had a period the week before. Just to give you a warning that if you get a (heavy) bleed now, it doesn’t mean you are still having periods.
Did you notice any cycle during mirena at all? I never was completely period free on my previous mirena, but I had some months where I would hardly spot, but I still had a cycle I was noticing.
If you might be post menopausal (could be, you are 52, so that is about the average age for menopause), you could take the utrogestan continuously (100 mg every night), that works for bleed free hrt for a lot of people post menopause. If you turn out not to be post menopause, and you really prefer to be bleed free, you could consider a progestin only birth control pill like Slynd as your progesterone part.
I’d try the Utrogestan first, to see how you do on it.