Is this reflux?

My little guy is 5&1/2wks. The last day or so he's been feeding constantly which I was taking as another cluster feed but he's been spitting up a lot too. Like he's eating too much, he's not fussy about the spitting up. He's been cranky about not being on my boob but when he's spitting up so much I feel like I need to cut him off. When he clusters he won't take a paci and is generally meh. My other kids had reflux and were miserable all the time especially before and when they spit up, he's not doing that so I'm just wondering if this is reflux or could it be a slight over supply?