What Causes Bump/lump On Labia Majora?

Hi, I have a bump/lump on my labia majora. I think it may be from shaving. I have had them in the past, but not often. I did have a genital wart/herpes scare from my ex-husband. However, I have been told by over the last 10 years that I don't have either. What could this be? I know that it can lie dormant. I am worried. It itches, but is only slightly painful because I have scratched some. I think it is because the hair is growing back. Can genital warts or herpes be detected by a doctor when it isn't flared up? does this make sense?