How long do you wait to go to the doctor?

There’s s a small bump on one of my vagina lips. It just red and looks like a zit that’s not ready to be popped but it’s big. I noticed it when I was shaving, i went over it and hurt it. I shave once a week and I always just go over the bump and it hurts but not tooooo bad. I never really thought about it til now.

Because I am shaving over it once a week, could that be the reason why it’s not going away? It’s been there for a month probably. The more I’m writing the more I’m freaking out. What if it’s an std or something??? But when I first noticed it, I hadn’t had sex for 2 months