I want on the depo for 3 year. been off for 5 months, had 3 period. when will i get pregnant?

It varies: you may want to have labs done to be sure you are cycling and ovulating after being on the Depo. You could be having anovulatory cycles.

Can't predict : Even if you hadn't been on DepoProvera, it would be impossible to say when you would conceive. I can say that regular periods suggest that you are ovulating and you should conceive within 1 year of having regular, unprotected intercourse. Otherwise, it will be time to start an infertility work up. Hope this helps.