Baby more satisfied with breast milk?

I have been supplementing with formula since day one. Once my milk came in, I started pumping due to poor latch and have finally caught up to her demand. I have even breast fed directly a couple times (not sure if she's getting anything out) and she doesn't want pumped milk afterwards. However, it seems that she is taking way less breast milk than she did formula. I'm worried that something is wrong because she isn't feeding like she used to. Is it possible that she is satisfied with less breast milk than she was with more formula? She is sleeping, peeing, and pooping like normal and she isn't fussy at all.