Baby Not Eating - is this normal?!

danirose. • emilia belle 02.08.16 evangeline lee 08.28.20
Might be a little long, but any help/advice GREATLY appreciated.
My daughter is turning 1 next week. She just started daycare for the first time two weeks ago. She goes 5 days a week from 11:30-6. Before that, she was going to a sitter's house 3-4 days a week for about 4-7 hrs at a time. She had 0 issues at the sitter. Since starting daycare, she hasn't been eating as much as she used to. I figured she's just getting used to the change, and if she was hungry, then she would eat. She still ate at home fine. Now, the past few days, she's hardly eating at home & eating even less at daycare.
 Today, she ate NOTHING at day care AT ALL (she usually at least has snacks if she won't take her bottle). So I bring her home thinking she'll want a huge bottle but she wanted nothing to do with it! I kept trying to give her different things so she would eat because she'd literally not eaten since 9:30am and now it's almost 7pm. I finally got her to eat something but now I'm afraid she's just not eating enough.
I mean, she's old enough to know if she's hungry to eat, right? Or is she not? She was previously taking about 30oz of formula a day in addition to table food 3x a day for the past few months. Last week, she was only taking about a 20oz of formula in addition to the table food. Today, she had 10oz of formula. I did call her doctor but they said to not be concerned if she's not sick or fussy (which she's not) and they'll address it further at her 1yr well checkup next week.
Anyone have any experience with this? Is this normal? A phase? Should I be concerned?