Really long period, can anyone give advice?

Started on microgynon 30 two weeks ago, on the first day of my period as told to by the doctor, and i'm still on my period.

Usually they last 3-4 days. after 3/4th day it's stayed in the "last stage" of period, where its dark and brown ish.

If anyone else had this, how long did it take to stop and for a normal cycle to come back.

I have a doctors appointment next week anyway (not about this) so if it isn't normal or if im worried i'll talk to her then, but i'd really like to know soon because being on your period for longer than you have to isn't much fun.

Thank you :)