Hi My Name Is Selena I Had The Implanon Inserted

Hi my name is Selena I had the implanon inserted may 15 2014. For the first couple of months I had normal periods now for about 7 months now I've been having them like 2 times a month. But my last period was 2 weeks ago and now im having light brown discharge. I don't understand what that means. I went to the doctor a little over a week ago and they said I had a bacterial infection. I don'tknow if its because of the many periods ive been having or maybe its from using douches sometimes when I get off my period. I'm not sure what it is. Could you help me out?