This is my cat sasha, she is showing signs of pregnancy but doesn't seem to look very big. She eats loads and her nips are very pink. She been spending lots time resting and washing her genitals
It's hard to tell without pictures of her standing up. Can you get one of her standing and one of somebody holding her front up with her feet on the floor, a good shot of her belly?
But. . .if she's not spayed and has been outside (or inside with an unneutered male), she is probably pregnant . Cats are extremely fertile.
The only way to know for sure is to have the vet take a look, maybe do an ultrasound. If she's not pregnant (or even if she is, and you're comfortable terminating the pregnancy), please have her spayed as soon as possible. She's at risk for pyometra and breast cancer, and the risk gets higher every time she goes into heat. Phantom pregnancies are a sign that her hormones are overactive, could add to the risk.