Kitten is on Clavamox; When should i end the course?

Vet said to give it for 5 days, but everywhere on the internet it says atleast 7-14 days (or until the bottle finishes).

What should i do? Should i keep giving it until the bottle finishes? 

No symptoms of URI other than sneezing every hour or so. Vet said he's normal but as a precaution i insisted on getting the antibiotics.

So, sneezing. Any sign of nasal or eye discharge? If so, is it clear, white, yellow, or green?

My guess is that your vet likely thinks the sneezing is due to allergies or a viral infection (like felime herpes virus) not a bacterial infection. So, if there is no bacterial infection, antibiotics aren't going to cure the sneezing.

In this event, 5 days of Clavamox won't hurt your kitten; but, anything longer isn't needed.

Nope. no nasal discharge no watery eyes, nothing like that. he seems perfectly fine. playing and eating fine too. 

Ok. Then, 5 days should more than suffice. (Though I tend to agree with your vet that they aren't needed.)

Now, L-lysine (a supplement) is something to look into as is Famcyclovir (antiviral) if the sneezing persists. Especially if there are no signs of infection.

omg i hope my cat doesn't have fhv or any other virus. but i will ask his vet about L-Lysine and Famcyclovir. Thank you.