Appendicitis is usually a relatively easy diagnosis to make in a young man as the symptoms and signs are progressive and ultimately severe, bloodtests confirm the problem, and there are few other potential confusing diagnoses.
You do not readily fit the picture i.e. pain for a week not really getting worse.
These types of symptoms often resolve spontaneously without a cause ever being found. Some people will have ‘a bug’, others may be a little constipated.
Grumbling appendix is unusual. I am not sure that surgeons even believe in it although to say that it does not happen is probably wrong.
I would simply take the advice offered by your GP surgery and see how things progress. If you deteriorate then go and see them again. If symptoms do not resolve in another couple of weeks then go see them.