Hi Steph!
I worried every day when dd was ebf, even periodically took her in weekly to the bfing clinic to get her weight checked

. She's rather small and has always had low weight gains. Many times I wanted to give up bfing because of the worry but then I would come to this site, call the local bfing clinic, reread over and over every detail I could find on increasing supply, latching, etc. Once she started solids the worry did not go away! Then it was a new worry- now that she's eating solids, will it decrease my supply, will I now not have enough, ah, the list went on! Only now I can say I don't worry (as much

).
I think it's 2 part- one, the fact that we can't visually see what they are taking in and two, the fact that they have MSPI and perhaps other allergies, this makes us fret more.
At 20 pounds, 5 feeds, and sleeping through the night, I think your lo is doing great!