My period after depo

So me and my boyfriend had sex about a month ago and it was about 3 months ago that I stopped getting depo provera shots. The sex was unprotected but he did not ejaculate inside of me (just pre-ejaculation) and my period after depo was coming every 10-12 days and now it’s been 17 days since I’ve gotten one. Should I be scared of being preggo or is this just my body adjusting after the shot? Help!