The way you usually decide if they've had enough to eat is to make sure there's more in the bottle than they can finish. Don't know ml, but with oz I'd typically put 0.5-1 oz more than I knew he could eat. AT 3 weeks old, that mean I'd feel his bottle with about 4 oz and he'd eat about 3. If he's draining the bottles at every feed, then he may be still hungry so fill it more. It's hard to waste precious formula 'cuz I know at least here some of the formulas are really expensive (my son had allergies, so we pretty much paid the price of gold per oz!) but that's really the best way to ensure LO isn't hungry.
The other problem just may be your A time isn't the right length. First off, why 2 feeds every awake period? Is there some reason you don't just give him 1 feed? A baby doesn't have to have reflux to get digestive problems when eating right before sleeping. Gas bubbles, tummy ahces, digestion can all be uncomfortable right before sleep so if at all possible it's best to follow the BW plan of feeding upon waking so that LO has the maximum amt of time upright before sleeping again.
At this age, your LO can probably handle around 60 minutes of A time. If you're putting LO back to bed after only 30-45 minutes, then LO is probably undertired. Then LO gets aggitated because not sleepy shoots past sleep window. Make sense?
as for getting aggitated, LO is just exploring his world! He won't always be a sleepy little lump of mush.
Sometimes he'll hear, smell, see (barely), taste somethng that seems interested and he'll get all excited. jThat's cool! When we warn about OS at this age, it can happen simply through handling your baby because EVERYTHING is new. So, if you have a touchy kid just changing a diaper can see stimulating to them. It's hard to know whether OS is going on here. I suspect it's an A time issue, if I read your post correctly.
