I'll give a real reply. If you grapple long enough, these types of injuries are bound to happen. Only you can really decide if it is something you want to go to a doctor for. Frankly, Doctors are not terribly useful for anything other than acute injuries requiring some type of major medical intervention. Soft tissue damage (which is most likely what we are talking about) will not show up on x-rays and standard tests, so the standard thing is for them to give you ibuprofin, maybe a steroid for inflamation, and tell you to take it easy for 4- 6 weeks in most cases.
First step to any injury like this is to take a little time off from training, even though it is hard. Take some NSAIDS for a few days, ice the injury, try to keep it elevated as much as possible etc.
It should be become clear within a week whether this is a small injury that will take care of itself pretty quickly, or something more major that will require rehabilitation and possible Dr visits.
Try not to rush back to training as it is easy to make things worse. For me at least, most of these take care of themselves eventually, although may leave you with a minor nagging injury.
