My pregnant cats kittens have been moving over three weeks she's so big she can hardly walk is something wrong?

Cats are pregnant for about nine weeks. Kittens can be felt moving at about four weeks, if there's a lot of them. As long as you can still feel them moving, and she doesn't seem to be in pain, then everything is fine. My cat was so round her belly almost dragged for the last couple weeks before she gave birth, so size isn't always a good way to judge how far along they are.