What Causes Vaginal Lips Swelling And Occasional Bleeding?

I ve been having discomfort around the vaginal lips area for about 2 weeks and occasional blood found when I wiped front to back after going to the bathroom. At first I thought it was a scratch or something from shaving that area. But now I don t know because it s been about 2 weeks with same discomfort when wiping and showering. I know that one lip is swollen closer to the anus. It s further back so I can t tell what it looks like. And if I should be worried. I am sexually active. With the same man for over a year if you need to know that. On birth control and only cycle once every 3 months