itching after sex???

so the other day i had sex with this guy i’ve started seeing - first time we’d had sex with each other - and afterwards the area around my vagina started itching a lot. a few red bumps, but nothing too crazy as far as a rash goes. i’ve been spotting since then.

we used a condom, a brand i’ve used before with no issues, so i don’t think its a latex allergy.

i’m pretty sure he doesn’t have any STIs (he said he doesn’t, anyway), but even if it was herpes (which it doesnt look like) or something i don’t think it’d show up that quickly.

it also doesn’t really seem like a yeast infection because i’m not having any of the discharge that comes along with a normal yeast infection.

the only thing i can think of is a allergy to his semen??? i know that’s really rare but it kinda makes sense since that was our first time sleeping with each other.

i know this is all over the place, but its been a few days and it still itches so i’m just kinda thinking out loud, trying to figure out what could be causing it. any ideas or similar experiences??