Welcome and thanks for posting your query to HCM.
After reading your query there are 3 possibilities in your problem
1. Sebaceous cyst: it is a simple swelling produced by proliferation of oil glands. It do not cause any pain or other symptom.
2. Lipoma: It is a collection of fat in the localized area. It may be soft to firm and It do not cause any pain or other symptom.
3. A growing lymph
node: This is proliferation of the lymph gland. It may or may not be painful.
IN your query you have not told since how long you have the problem or any associated symptom. So there can be any of the above possibility. You just wait and watch, most of the swelling subsides by its own. Do not try to pinch or squeeze the swelling.
With good health wishes
Dr. Sanjay Kumar Kanodia