Hi! Hormone blood tests are reliably un-reliable!
Menopause literally means the last monthly period. No more. Ever. One needs to have been free of bleeds for at least 12 months to be post. Your body may have got there on it's own if you had the Mirena.
As oestrogen levels drop muscles may become lax = aches and pains. Also the body may become dry : skin, scalp, eyes, deep in the ears, nostrils, vagina

browse round. Make notes

Maybe keeping a mood/food/symptom diary will be useful?