...your newborn had green poop?

DS (7w) is my 3rd kiddo, but is totally different GI-wise! He is a spitty baby but never seems bothered by it, so I'm pretty sure he's just a happy spitter. His poop is green about 50% of the time; every once in awhile has a bit of mucous, but it's not super-slimy, and I've never seen blood. I do have a bit of oversupply and fast letdown, but it's never frothy and I only feed one side per feeding, so I don't think it's related to foremilk/hindmilk. Even with the spitting, he is gaining weight and growing like a champ (averaging >1oz/day gain). And overall he is a calm and happy baby who sleeps & naps well.

Our 2m appointment isn't until next Friday, and I plan to bring it up with our ped then. But I figured I would crowd-source in the meantime