Bump on upper Vulva?

I have a fairly painful lump under the skin of my upper labia. It’s not painful enough to limit my movement but it is sore to the touch. I have no idea what could have caused it. I’m sexually active but with my monogamous partner of 2 years. I do shave every 2-3 days but I’ve never had this problem before. Any suggestions? I really need it to ease my mind.