Eating amount question

So baby girl, 5w2d old, ate 27ounces two days ago, 23ounces yesterday, and only (so far) 17ounces today. She has given cues she's hungry all day so I will nurse her for a few minutes until she gets really fussy and than she gets a bottle. Sometimes the bottle is breastmilk and sometimes it's formula. Does anyone else's lo eat like this with such differing amounts? I'm going to our LC tomorrow and will ask her-just wondering if anyone else is experiencing this....?