Are the unborn kittens dead?
You have to take her to the vet for a checkup. Sometimes they will expell the kitens if they are dead, but often this late on they won’t. If this happens the kittens will rot inside the queen. Obviously this is not good news to her health and you may lose her too. It’s also possible your cat may have some internal bleeding especially because of the extra load she is carrying inside that is not always obvious until it’s too late. There is also the chance she could go into premature labour. At this stage there is little or no chance any of the kittens would survive so again an emergency spay could be done. Why put her through labour when the kittens would not live anyway plus she does need to be spayed anyway whether it’s now or hopefully after the kittens have gone to new homes. As another poster said it only costs $20-$30 to get her checked out. If you vet can’t find heartbeats he can spay her right away and hopefully all will be well. if there is any internal bleeding that can be take