If you have unprotected 4 days after getting the depo shot can you get pregnant. ?

Short answer is yes.: If you had the injection in the first five days of your menstrual cycle, it should start working 24 hours post-injection. If you had the injection after the first five days of your cycle, it takes 14 days to work. No form of contraception is 100% effective, so pregnancy is always possible with sexual intercourse, but Depo is typically very effective. Only condoms prevent STI's!