Hello, you don t need to worry for your periods. It will come back within 4-6 months after the body has adjusted its hormone levels. Implanon is a hormone based contraceptive which is effective only for 3years. You can get pregnant with expired implanon as the hormone it was releasing is finished and your status is you are using no contraceptive at present so there are chances of conceiving without periods similar to conceiving in lactational amenorhoea. Therefore if you do not desire to get pregnant then remove the expired one and get a new implanon inserted or use ocp or injections as per your choice.