Periods with Mirena after breastfeeding

I had my Mirena inserted about four months after my daughter was born and bled for a few weeks after insertion and then not at all until I stopped breastfeeding about 9 months later. For the past few months, I’ve had periods that are getting progressively lighter but with A LOT of spotting in between. Is this normal? Did anyone have similar experience with Mirena after stopping breastfeeding?