Hello, I would be happy to help you with your question.
You are right, implanon
is supposed to remain in place for only 3 years, but there is a certain amount of hormone present that is still active for some time after that. Over the last 2 years (you did not indicate) I would assume that you had some resumption of normal cycles? Once you are having regular cycles (which might be delayed if there is still hormone in your system) then the chance of conceiving every month that you try is about 15-20%. 85% of couples will conceive within the first year off of birth control. If you have irregular cycles, you need to talk to your doctor.
I hope that this helps and good luck!