Bump in vagina

Hi. So I have a bump on the vaginal opening, it’s not in the vagina but just where the opening is. It is painful. I’m not sure whether to be worried because I go walking daily and sometimes get bumps on the sides of my upper thighs from sweat build up but have never had it in the vaginal opening. Everytime I pee and wipe it really hurts so I’ve been terrified to go pee. I’m not sure if it’s bleeding or not because I got it yesterday, and then started my period today. Not sure if I should wait it out and see if it goes away on its own and wait a few days, or head to the clinic tomorrow. Has anyone ever experienced this before??