Possibly A Dumb Question But Thank American Sex Ed Quality

Me and my boyfriend have been having sex.. very frequently. Through the past week. And. We haven't exactly been using condoms. He always pulls out well before ejaculation but sometimes he cums a little close.. and it runs down my labia...

Could I possibly get pregnant if it were to run downwards to my vaginal entrance... or is it true that sperm dies upon exposure to oxygen?