Unsure if it’s reflux or gas

My 5wk old has been getting fussy during his bottle. He’s a formula baby and we use Similac and Dr. Brown’s bottles. He spits up a ton but it doesn’t seem to ever bother him however lately he starts to cry mid-feed. I’ve tried gripe water which doesn’t really work and of course burp and try tummy massage, bicycles, etc.

What were some key signs to differentiate reflux vs gas for your babies?