Dry Humping scare ! there's that saying, "it only takes one"

My boyfriend and I were dry humping about 5 days ago. He had on underwear and polyester sweatpants, whilst I had on cotton panties and cotton pants. We did it for a while, until he pulled his pants down (not his underwear though) and he looked in his underwear and saw that he had pre-ejaculate. It had dripped down the side of his part, and he pulled his underwear back up. Without pulling his sweatpants back up, we kept doing it. All this time I had all my clothes on.

Also, he can't remember if he had put his hands in his underwear or not (to check for the pre-ejaculate) and he had proceeded to touch me from right outside my panties. He had slipped his hand in, but didn't get anywhere near the opening (he just touched the skin)

and there weren't any stains on either of our clothes (except his underwear) or anything as far as we can remember

So I have a few questions

1) would his sperm, from the pre-ejaculate, have been able to go through his underwear and through my pants and panties and reach my vagina?

I know it's a ridiculous question but sperm is microscopic and there's that saying, "it only takes one".

2) Say he did touch his penis to check for pre-ejaculate, and then proceeded to touch me through my underwear. Would there be any risk of his sperm, from his hand, getting through my underwear?

I do remember that his hands weren’t soaking with semen or anything; they felt pretty dry. But again, I was wet myself so I guess I wouldn't really know.

3) And if he put his hands in my underwear (just the area with skin), would the sperm (if there was any on his hand) be able to get near the opening and travel up my vagina?

I know these are crazy questions and I sound like a paranoid freak, but I am just so scared of being pregnant.
I’m only 17 years old
And I know, “use protection” “go on the pill” “get educated before messing around”

Sometimes, things just happen when you’re in the moment, and it can really screw things up.

Please I just need some insight on this.

Could I be pregnant?