Lets be real here. In cases like this, there is sometimes a super tiny chance that somehow his sperm ended up somewhere other than where he put it, i.e. fingers, toy, mouth, kneecap, whatever your into basically, and then ended up in your vaginal region. Almost like the notion of cross contamination, or like his sperm hitched a ride in on some other unsuspecting object or organ. This absolutely can and has happened, but frequently cases where people believe that they got pregnant in such a fashion can be chalked up to the heat of the moment. People forget exactly what went in which hole when, or who licked who where, etc, or maybe were so caught up in the moment they didn’t even realize it happened. But sometimes sperm do hitch a ride over on a hand or on the lips or from having genital contact without penetration. But the situation you describe, as I understand it anyway, seems like a super super extra low chance of you being pregnant, and this kind of transmission isn’t exactly common to start with. It doesn’t even sound like you made contact with his sperm. The only possible way with an extremely low chance, and I mean literally miniscule, is if you gave him oral first, he got some pre *** or something in your mouth, then you heavily kissed him, and THEN he went down on you.
There is absolutely no way to get pregnant from oral sex. Seeing this makes me worried if you are old enough to be having sex. Make sure when it goes past oral you use protection. Stay safe.