Itchy vagina after sex

I had an unprotected threesome whilst drunk with a woman and man. A couple hours later when I woke up a notice a very very subtle itch inside my vagina and then the next day it got a bit more intense and the day after (today) has been pretty itchy… it’s not on the outside, it’s on the inside. Ive noticed no unusual discharge …. It definitely smelled like I had unprotected sex. Not a bad smell but just not my usual smell… very off. Idk if its my ph levels or abrasions or an infection or an STI. I’m scared.