my cat had kittens 9 weeks ago but still has not come into heat?? she is booked into vets to be done but i could not do it before as she was really poorly!!! she has got out a few times as one of the kids has opened the door is this a bad sign??????
Yes, she's almost certainly pregnant again. Cats can go into heat very soon after having kittens, especially if the kittens die quickly. And it's not always obvious. If she's not too far along the vet can still spay her. . .so get her in ASAP!