Could it be that he's moving on them or is it too tight?

The size one I tried fits like half of his body but the newborns make little red marks on his legs:/

I learned the hard way, if they poop out the diaper it's too small lol

@mommysbabies, ok thank you both:)

If it leaks it's time to switch

Put a size 1 on and see how it fits :)

@kmharr3, I mean I'm not sure because it's pretty snug fit and doesn't seem too tight right now I guess I could try a size 1 on and see if it better. I just know if the diaper is loose he'll pee out of it.. :/

Dont go by weight, go by fit. Some babies carry their weight in their thighs and butt and may need a larger diaper

Once it's too tight it doesn't fit properly anymore you get a size higher