Thank you for asking. It warrants a detailed physical examination. Your description is very non specific. Multiple injection or conditions can present in such a manner. Other associated symptoms of Itching, redness, course of its development, sexual history, etc needs to be considered.
Next Steps
My best advice to you is to show yourself to a sexologist or dermatologist.
Health Tips
Don't worry. It doesn't appear to be a serious. It can be cured.