Could I be pregnant?

Basically me and my partner ain't had sex in a year and a half, after I had my son, I went on the depo shot. I only had one shot and never bothered to go back for second one as we weren't having sex. Anyways last night me and my partner had sex unexpectingly, like I didn't think we would at all so I've not been protected, but my partner didn't ejaculate so we just stopped. My question is could I be pregnant even though he didn't ejaculate? I'm going back on depo shot now as I'm not taking any more risks, but I'm still worried I could be pregnant from the sex last night. Please no haters I know I've been really stupid😫