My Rabbit has not ate or drank anything today?

She built a nest yesterday (out of instinct she is 100% not pregnant) and since then has not ate or drank. She has not ate her pellets but she will at bananas and treat like stuff. ( I only gave her a little bit/not replacing her food). So I was wondering if it is instinct to stop eating while she thinks she's going to have babies. THANKS and if you may know why tell me! She doesnt like hay, so is it possible she has ingested too much hair? She still poops and urines. And is acting completely fine.