Growth Charts, Weight Gain Anxiety Hell, Looking For Similar Experiences

I’m really puzzled by my baby’s growth/weight gain and looking for insight from anyone who has experienced something similar.

First, I have had an appointment with an IBCLC, it was kind of a disaster because it was her worst feed ever, the consultant had an incredibly loud voice and it distracted my baby and I couldn’t get her to latch which usually never happens. Despite it being a terrible feed, she gained an ounce from one side for 5 minutes so the consultant told me we are doing great, and not to worry.

This is my second baby, she is 11 weeks today. Her growth has slipped from birth at 46th percentile (but I had an IV and she was FULL of amniotic fluid from a very quick birth) to 11th as of 9 weeks. Our pediatrician has said she is not concerned but also keeps having us come back for weight checks.

Looking at my baby I’m not concerned at all, she’s chunking up, nurses 8-11 times a day, has at least 5 poopy diapers and lots of wet ones, she’s meeting all of her milestones and is content and engaged. She’s not fussy, she sleeps very well, and generally gives me such an easy time for a newborn.

However, she’s only put on half a pound since our last weigh in two weeks ago. My first kid was consistently around 80th percentile so I’m not used to this at all. I’m starting to get really stressed out but I can’t see what the problem could possibly be since her output looks great and she’s happy???

Is it possible she’s just petite and her birth weight wasn’t a good indication of that?