Small hard vaginal bump on labia no discharge negative for all stds. Hurts when skin is stretched around it. Been there months. Any idea?

Cyst vs. Wart. It is fairly common to see different types of cysts in the vaginal area. Sometimes they are related to infection or trauma. Also, genital warts can be found in this area. I would recommend seeing an ob/gyn for an exam to determine what exactly it is and what, if any, treatments are needed.