Will's old boss had that happen to her. She would tell the story WITH PRIDE. It was creepy. She's not exactly a "dainty" woman, so it wasn't a complete surprise to me that she didn't know she was preggers until her daughter was about to pop out. She said she lost weight during the pregnancy, never was sick, and had a "very irregular cycle" from ovarian cysts. She was deemed sterile by all her doctors, too! It just never crossed their minds.
Personally, I would wonder what she thought her daughter kicking was. Did she just think it was gas? Or was it that whole live goat that she ate?
*scratches head*