Still no foal...

Last night at around 10:30 I went outside to check on Nacoma and she was laying down moaning and all sweaty (those are signs that she is about to foal) so I stayed outside with her for about an hour till my mom came out to check on her too. she sat in the stall with me for a wile and Nacoma was still laying and moaning and wouldn't  eat anything and I have never ever seen Nacoma turn down food of any kind so we truly thought she was going to have the baby soon or at least that night. so we watched her until 12:00 and decided it was time to get some sleep then was our only chance considering if she had the baby that night we would be up all night with her and the baby, so we went in and went to bed.  we checked her again at 2:00, again at 3:00, again at 4:00 and again at 5:00. at two  she was still laying down like she was going to have the baby any minute, at three it was the same and at four she was standing up eating hay like nothing was ever wrong  and at five it was the same. So guess what? STILL NO DARN BABY :(
My Mom and I are just baffled that she hasn't had it yet. my Mom called the vet this morning and the vet said you never really know when a horse is going to have a baby, and that its just hit or miss sometimes.