How long does the implanon medicine stay in your system?

ok. I am an unusual case. I was in a near death car wreck in \'04, which resulted in a lot of serious medications. I condtracted MRSA from the hospital and started having seizures. I\'ve never had seizures until I caught that staff infection. I was on a newer drug called Trileptal that the doctor said I should not get pregnant because of the possible birth defects the child could have. They put me on the Depo but that made me gain so much weight, I switched to the Implanon. My husband and I are going to get it removed tomorrow so we can try to have a child. My question... how long should we wait to try to have a baby? How long does the medicine stay in your system?