Hey, MommyAdamo ~ from all I've read on the boards, this is a perfectly normal thing. My DD goes through days where she eats 7-8 ounces for all her feeds, and other times she takes just 2-4 ounces. I'm careful to keep her feeds 4 hours apart so as not to encourage snacking, but I do worry when she does that, because she'll likely get hungry and wake up too early from her naps! Most days if I can get to the 20-25 ounce mark, I'm happy.
Anyway, my LO is "supposed" to be taking 6-8 ounces per feed, so if I see she's only taken 2 or 3 ounces, I will wait 20 minutes or so and try again. And during the wait, I will keep her in the "feeding area" so she knows it's still meal time. So, like a mini-feed at 10, and then another go at 10:30. Usually she will take another 2-3 ounces at that time. Then, here's the thing, I have to adjust her next feed so it's 4 hours after the 2nd try, not the 10:00 feeding. Otherwise she's actually eating too often and it encourages snacking. Tweaking the EASY routine by 30 minutes doesn't usually throw us off course too badly, and it's a way to make sure she gets the calories she needs. I don't know if other BW moms do this, but it seems to work for us.