I've had the birth control implant for about a year now and, except for light spotting the first two months after insertion, have had no periods since. Recently I took the antibiotic keflex after having my wisdom teeth removed. I called my doctor and she said that the keflex would not affect my birth control. With four days left of the keflex I suddenly got a period. I called my doctor again, concerned that my birth control was in fact being affected. She assured me that random periods, even after a year with no periods, is a normal side effect of Implanon. I'm just not so sure though that the period was random. I believe it was caused by the keflex. Will I eventually stop having periods again, or am I stuck with this for the next two years I have my implanon in?