Rapidly growing newborn

Am

My son turned one month today. Was 8lbs 8oz and 19in at birth. Today he is 12.3lbs, 23in and already in size 2 diapers and 3-6 month clothes. I’m sad cause we spent so much money on size 3 month and size 1 diapers. I was totally relying on my first babies growth. Hopefully this little man slows down! 😅