What Causes Brown Color Discharge And Weight Gain Removing Implanon After ?

hey i'm 19 years old and i had the implanon since oct of 2010 and i have been having a white/brown chunky discharge.i have already been an std test done and everything came back good. and i also notice that i have not been gaining weight but losing it im very small 5ft and my weight was 113 and now its 106 i want to know how come i having been gaining weight. and i also want to know if the implanon cause cold sores because since i had the implanon i had 3 cold sores and shea butter seems to help if i notice it in time but is there anyway to stop the cold sores?