I'd give it time. If he is still eating, pooping, peeing and normal weight (no quick extreme weight loss) I'd wait.

Sometimes my ginger cat will "sit on a hairball" for days refusing to puke it up. He acts miserable, pecks at his food, pukes his food, pecks some more etc.

Felines are great at masking illness and can even skew their own blood work.

I'd try the olive oil, Vaseline, or butter on the paws route to assist with a hairball first.

What's he puking? Food or yellow stomach acid/bile?

Don't give up on him,wait a while and it may work itself out. I once had a cat who ingested some fiberglass insulation we believe and he was puking miserable for more than a week before he was better.

Also l-lysine is good ground up in wet food for cats.