calis getting big fast!

cali has blew up in the last 24 days she is a really small cat to begin with, and still looks like a kitten even though she is over a year old, she has just gotten the pink nipple sign but her belly is really big! she looks wierd because her belly is bigger then her rib cage. Is this a sign that she will have alot of kittens or is it just because she is small? Im also afraid that she isn't eating enough she looks really skinny and I leave food out all the time, ive had her tested for worms and the test came back negitive, im afraid the kittens are taking more out of her then she can handle. Am I just being paranoid or is this normal?

Well, it sounds like you're gonna have alot of kittens!