Implanon irregularities

Is anyone else on the implanon (stick in your arm) and experiencing erratic menstrual cycles? I've had my birth control for a little over 2 years and I love everything but how crazy it's made my cycle. It has lightened how much blood is discharged and has helped tremendesly with my pms attitude but my last period was 2 FUCKING MONTHS LONG!!! What the actual hell... Anyone else? Is this normal?