Implanon

I've been having the Implanon since Jan 2014 and I've had a menstrual cycle with it and all of a sudden it just stopped. My last cycle was August 20th- September 4th, 2014. I know there is no way that I can be pregnant, I've taken several test. I am concerned as to while it would stop my cycles all of a sudden. I read that after a year that it can stop your cycle, but I haven't had it in a complete year yet. I may be over reacting but this is freaking me out!