S.B.
My son was 9lbs 8oz 21in at birth - at 2.5 mths was 14lbs 9oz 26in - at 4mths is 19lbs 14oz 28in. My Pedi said they are suppose to double their weight by 5-6 mths and triple by year. I am bf...he was off the charts with his height and in 95% with weight...LOL My Pedi is fine with it because he was big to begin with and is nice & healthy! No worries!