How long was your first period after you had Mirena installed?

Stephanie
So I got my Mirena installed on 9/21, on the last day of my period. Apparently my period decided to come a week early and now I'm on my 9th day of my period. The bleeding isn't terrible but the cramps are excruciating (but only for a few seconds). How much longer do I have to look forward  to this? And how long were your first periods with the Mirena IUD?