Ridiculously long period? Oh okay.

Shelby
Hello ladies! 
I got the Mirena about three weeks ago. Had no problems with insertion and not much cramping. But I've been having my period for nearly 2 weeks now which is lame. I remember when I first started the pill back in the day that I had a couple of long periods before they got more regular and short. Should I expect the same thing to happen here?