New Mirena IUD Questions

So I got the Mirena back in November after having the paraguard for over 4 years. My periods have been weird and I just want to see if anyone knows if this is normal or not.

November: my regular heavy period

December: light prolonged period then nothing throughout the rest of the month

January: when I believed my period was (I was cramping and my app said I was due) there was nothing. Then about a week ago I started bleeding lightly, now I’m starting to bleed more heavenly.

Is this normal? Is my body just getting used to the IUD?

TIA!