Hi, D.! I have a couple questions for you. First, how tall are you and your husband? Were either of you small as children? Second, did you breastfeed or are you still breastfeeding your 2 year old?
Let me tell you about my daughter. She was born about 4 weeks early and weighed 5 lbs, 14 oz. She was nowhere near the 20 pound mark at her 1 year old checkup. She just barely hit 20 pounds by her 2 year old checkup. She also was not on the charts for her height.
I am 5 feet tall. My husband is 5'10", but his parents are about 5'7" and 4'11". So even though my husband has some height to him, my kids come from a lot of short people! Also, I breastfed my daughter until she was 16 months old.
My daughter was always healthy and happy, but VERY small. When we'd go to the doctor for a sick visit and have to see someone other than our regular pediatrician, the doctor would always express big concerns about her being so little. I was told more than once by more than one doctor that my daughter was "too little" and needed to be seen by a specialist. But as her mom, I knew she was healthy, so I was in no rush.
At our next well child visit after doctors had started tellings us there was a problem, our pediatrician (who I love and really trust) said NOTHING about her being too small. I asked her if she had concerns about her size and told her that other doctors in the practice had told me she needed to see a specialist. She just smiled and said that considering the size of the people in her family (father excluded, although he's not SUPER tall either), she probably isn't going to be very big ever! She also told me that when a baby is breastfed beyond a year, they tend grow at a smaller rate between that year mark and the time they are weaned, which kind of puts them behind the growth curve. She said there was nothing wrong with nursing beyond a year, that it had health benefits beyond a year, but that it has been noted that breastfed babies tend to be smaller. She said there was nothing to worry about since my daughter was healthy and developmentally on track.
Now, my daughter is almost 5 years old. She is still the smallest kid in her class at preschool. People usually think she's about 3 until they hear her talk. She wears mostly 3T clothes, some 2T clothing still. She's smart, active, healthy, and TINY! I have no worries.
My point in telling you all this is that you may not even need to see a specialist. Some kids are just little! If you and/or your husband are short or were very small as children, consider that! If you breastfed beyond a year, consider that! I was very educated about breastfeeding and knew that breastfed babies tended to be smaller, but didn't know that nursing beyond a year kind of put us in another category. I hope this eases some of your fears. I know that if I had seen a specialist and they had wanted to put her on some kind of hormone therapy or something, I would've said no way. If your little guy eats decently and is developmentally on track, I'd trust your gut. Also, if you decide to see the specialist, remember that you are the mom and you can consider what the specialist says without necessarily doing it. Best of luck to you!