Could I be pregnant or end up pregnant?

So just now, my boyfriend finished himself on my butt, we didn’t have sex just fooling around. Well I was wet at that moment and so I couldn’t tell if he accidentally got some on or near my vag or if I was just wet bc most of it was on my butt I wiped it off immediately after. I’m on my fourth day of my period, and my ovulation doesn’t start for at least another week or more. I know sperm lives for around five days in the vagina right? So could I become pregnant? Or am I? Sorry if this sounds like a dumb question I just want to be prepared.