[Question] Pain in left hand knuckle

Hey all I will likely be seeing a doctor soon just to be completely safe but I would like to hear if anybody has experienced a dull pain between the knuckles of the fretting hand, specifically between the ring and middle, and ring knuckle itself. Im just wwondering if this could possibly br a normal strain or something. Its never a sharp or shooting pain but more of an aching. It only varies a bit, usually getting better after playing for a bit. Not sure if the cause could be simply overuse or positioning but I will be looking into that as well.