It is highly unlikely..although doctors do usually recommend using condoms the first 2 weeks after your very first injection. Take a test before you get your next shot to know for sure.
Can I Be Pregnant After First Depo Injection?
Yes you can, there isn't anything to prove that you wont get pregnant. It can take anything from 2 weeks up to a month to kick into your system . I would do a pregnancy test if unsure.