I had someone drop off a beautiful cat a couple weeks ago and we have taken her in because she is pregnant. She was noticeably pregnant when she showed up but now she is huge. She doesn't even want to climb stairs because she is so big. I can see her kittens moving across the room. She has been sleeping a lot and she will get up move about 6-7 feet and just lay down again. I don't know anything about a cat giving birth. Is there any sure signs of when she will have the kittens?