She doesn,t look in foal to me but saying that when I was a child a pony at our local riding school suddenly produced a foal, she didn,t look pregnant and was still being ridden in lessons right up until she had it.
It was the same with Bunny, she was scanned empty in September, and didn't start to show until 4 weeks prior to foaling when she started to bag up. It was only in the last two weeks that her tummy dropped and started to show any sign of a foal being in there! My vet put a hand in when she started to bag up and he felt a foal in there.
I don't know how my vet managed to miss the foal in September though!