Hello,
From the symptoms it sounds like an epidermoid cyst. It is a benign cyst which can be caused by a blocked pore adjacent to a body piercing. It needs to be excised when infected/painful or when cosmetically causing problems. My sincere advice would be to discuss this possibility with your dermatologist.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your dermatologist. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.