I have a hard itchy pea sized bump on my vagina. & i'm not sexually active. what is it?

Many possibilities: There are different causes for bumps in the vaginal area. Bartholin's gland cysts, gartner duct cyst, ingrown hair, inclusion cyst, etc. If you are not sexually active then you don't need to worry about other causes associated with stds. Try using a warm compress with a wash cloth and place it for 20 min three times daily. Make sure you are using good hygiene as well. See an obgyn if its worsening.