I posted before asking if anyone knew of any websites where you could put in your child's height and weight over a period of time and it would graph it for you. I got several suggestions for sites that would give you a one time estimate of the percentile range.
So I wanted to share this in case anyone else is interested:
http://www.who.int/childgrowth/software/en/
The World Health Organization allows free downloads of their Anthro software ("WHO Anthro for PC"). It looks like it is intended for healthcare providers, but it is simple enough for anyone to use. I downloaded it and I put in C's height and weight (or just weight if that is all that I have) for a variety of dates and it does a number of graphs and saves the information. It tracks a lot more info that I need, but still is helpful.
These are the WHO percentiles, which may be different than what your pedi's office uses, but it will give you an idea if your LO is on a consistent curve and is supposed to be a more accurate representation for breastfed babies.