Obscenely long period on liletta

I got a hormonal IUD inserted not too long ago, and this is my first period with it. The problem is that my period has genuinely lasted 11 days with no sign of stopping. To be fair, the last 5 or 6 days have been brown spotting about 3 times a day, but it is still very annoying. I know periods are longer in the beginning until they get shorter (I think), but 11 days seems excessive. Is this normal?