I'm not sure what it is. When I woke up this morning, things were fine. Overall, things have been fine. It's just at certain points of the day, my left hip gets really tight, down to my quadricep, and then at times my left knee will just have a sudden shot of pain and then be fine. Going down into a full squat isn't really painful though. It sometimes happens when I am merely sitting. Maybe things will get straightened out. If I didn't have something to do here on campus later, I would have driven home to talk to one of the physical therapists at my gym.
Next time a doctor tells you to do virtually nothing, don't listen to them. Do something. Maybe nothing strenuous, but do something.
Oh, if this helps any, there isn't any swelling.