Hi ! Good morning. I am Dr Shareef answering your query. The sore lump in the pubic region could be due to a infection any way immaterial of an STD or otherwise. If I were your doctor, I would first go for a broad spectrum antibiotic along with an anti inflammatory drug for about a week time. If it does not get resolved, then I would go for some routine investigations like a complete blood count, blood sugar, and also would consider your referral to a gyanaecologist for a clinical examination and further management for possibility of an infected cyst over there. I hope this information would help you in discussing with your family physician/treating doctor in planning your treatment. Thanks for using the health care magic forum for your query on health. Wishing you an early recovery. Dr Shareef.