How common would it be for someone to get pregnant after coming of depo-provera shot if they haven't had periods yet?

Possible: A woman could ovulate as soon as 4 to 6 weeks after stopping the shot for b/c. Ovulation occurs 14 days before the period would come. If conception occurs with the first incidence of ovulation - there would not be any periods.

Could happen.: Usually the Depo-Provera takes longer than the 3 months to allow the ovaries to ovulate. It can still happen but usually it takes a little longer than what the description is to get it off your system. Do not depend on the Depo-Provera aftermthe 3 months, i recommend other method of contraception immediately.