Problems with my V

Hey guys need a little help here :) After a long day at my sisters college grad I came home and noticed not only was down there a little itchy but I had some weird discharge and my “lips” were very swollen. I called my sis and she said since me and my SO had sex yesterday it might be caused from irritation from that. Or it could be a yeast infection. What do ya’ll think? I googled it and if it’s a yeast infection what do those get caused by? One listed was pregnancy, which I dont think I am but I get paranoid haha. Let me know any advice you guys have as I would like to know where to go from here ❤️