By 2 months we were in 3 months clothes not 0-3m but 3 months +. Now she's in 6-9 months at 3 months old 🤦🏽♀️
My son was 8lbs3oz at birth and stayed in NB for about a month maybe slightly longer
All babies are different lol my daughter didn't get into Nb until 4 months and then she lasted up until 6 months and I put her both in nb and 6-9 months and she wore those until 11 months she's now in 12-18
My baby cant fit some of her newborn stuff now. But I think it depend on the brand and material also cuz some stuff I think she can wear a lil longer
3 months and still counting