DD is usually a great eater, but lately there are some times where she will fight and scream and cry when we try to feed her. Like today she hasn't taken a bottle since 9:15 am. I tried at 1:15 pm before her nap and she fought me, then I just tried again after her nap and she fought again. Is this normal? She usually goes anywhere from 3-4 hours between bottles and takes 6-8 oz.