Could be a cyst, that is the most likely cause. Not dangerous at all in most cases, and your doctor will be able to acertain the best way of dealing with it.
But the pain of appendicitis is also located in the same general area, and there are more serious conditions that could cause the pain as well, so waiting for your doctor's verdict is the best course of action.
Don't worry too much, though. Unless the pain becomes acute, it's not urgent. If it does, I'd strongly suggest going to the ER.