I have developed a bump on my right outer labia. It is painful to touch or when pressure is put on it. It is somewhat pinkish. It's bigger than pea size, maybe a very small marble size. Does anyone know what this may be?

(I have only had one sexual partner, I don't think he's cheated on me as he's very busy and has never lied to me before, I have recently gotten an infection from an ingrown hair because I was stupid and used a bad shaver too long. Is it possible it's also from that shaver? I used it there too)