Swelling!!!

In the middle of the night my right labia swelled and I couldn't sleep because of the discomfort. I woke up this morning and the swelling has went down a little but it's still red and tend to the touch. And I have white discharge. However there's no itching or stinging when I pee. Does anyone have any idea what I could be. Iv only has protected sex with one person every time so I'm more than sure it's not an STI and I have a doctors appointment in the morning. Does anyone have any idea what I could be!?!??