LO is 2.5 weeks old, was 7 lb 9 oz at birth and is 8 lb 3 oz as of yesterday at the doctor, so he's gaining weight pretty quick. We are still in NB diapers, they seem to fit ok, no blowouts, but I am wondering when most people size up?

I have about 30 NB diapers left (and he poops like 10 times a day so we go through them super fast). I have a box of size 1's, but wonder if I should buy more NBs first. We've put him in size 1 before when we were running low (last week) and they just looked huge.

What was your LO's size/how did you know it was time to go from NB to size 1?