Implanon birth control and periods?

I have been on the implanting birth control implant that goes in your arm for a little over a year and I have loved it up until last month. My period began on January 11 and today is February 1. That is a 22 day long period so far. It is heavy and times and at other times it's so light that I can only tell when I wipe. Can anyone tell me what's going on or give me some advice?