How long did your baby fit in newborn clothes/diapers?

FTM here. From everything I saw on the internet while I was pregnant, I was preparing for the possibility that my baby wouldn't fit in newborn sizes for long. My baby was born at 8 pounds, 7 ounces and 22.5 inches long, so I thought for sure he would only last like a week or so before sizing up. Well he's 4 weeks now and still has some room to grow in newborn sizes.