Thanks to everyone for helpful and supportive comments.
I doubt that the problem in this case is something I ate, or something hormonal as A) Bean refused the breast before she even latched, so she didn't even taste the milk, and B) she was perfectly happy to drink the milk I pumped this morning. So in this case, I don't think taste is the issue.
But I didn't realize that you could have an ear infection without a fever. I called her doctor today, and she said that either teething or an ear infection was the most likely culprit for a baby Bean's age. So we have an appointment for tomorrow morning to get her ears checked.
I still feel a twinge of fear that she might be weaning, but I know that's more of my own fears than the most likely scenario.
Of course, she could just be supporting the ongoing writers strike, but I guess that's not very likely either...