I would not do anything right now, continue to OP and monitor the condition. Chronic conditions, especially past injuries, etc have toxins/fluids surrounding the area and always right before an area is being healed it will often feel worse before disappearing forever. It is likely that although you felt no pain there, there were still surrounding fluids, etc and the oil pulling is getting the toxins out of the area and it is merely sensitized while it is doing it. I would not worry about it, I am betting this is a GOOD thing entirely - you will probably have a number of things in the months to come you will feel surface such as this. The OP probably just unmasked the condition.
Hang in there!