Is it possible to get pregnant 3 weeks after ending depo?

Possible: It is possible, but unlikely. One of the problems with Depo Provera (medroxyprogesterone) is a delayed return to fertility. That being said, there are numerous cases even in my own practice where women have gotten pregnant the month or two following cessation of Depo-Provera provera. In general, i tell my patients it will likely be 6-12 months before you are fertile again after stopping depo, but anything is possible!