What Causes Pain In The Left Fallopian Tube Area?

hello... it will three years since ive hadd the implanon birth control in my arm in june 2011. ive been to the doctors lately and they couldnt find it. is there any possible way that i can still get pregnant?? And also ive been having throbbing pains in my left fallopian tube area. could you tell me what that may be?