Swollen labia??

Something really weird is afoot with my vulva so I’m just gonna go straight into it... about 30 mins ago I took out my memorial cup, rinsed it and reinserted it. I’m nearing the end of my period (day 4 or 5), and right afterwards my labia started feeling really itchy (this is pretty routine at this part of my cycle ahaha) so I itched it a little bit, but not aggressively or anything...

right after I realized that my inner labia felt swollen. Upon further inspection I realized that it wasn’t only my labia, but it circles around my vagina to be swollen right behind too. I don’t think my itching it caused this because I’ve scratched my vulva way more aggressively before without it swelling up at all. I’m pretty concerned because this seems really strange. Can someone please tel me what’s going on???