You really should not be breeding unregistered, non-purebred cats when there are so many kittens being killed daily in the shelters, and for various other moral reasons. Do you know the entire genetic backgrounds of your cats to be sure they are not carrying any diseases or genetic problems that they may pass down to their kittens. Are you an expert on their breeds and know that they are an excellent speciman of their particular breed? If not you are doing what is called "backyard breeding". Are you ready to pay big bucks if there is a problem and your cat needs an emergency c-section in the middle of the night with an emergency vet?
Please consider spaying and neutering and adopting a kitten or two from a shelter. If you really want to see them being born and experiencing it all, you can foster a pregnant mother from a shelter. They would be forever grateful and you can then adopt the kittens. Please don't add to the overpopulation and spay and neuter your cats. Please check the forum rules too about backyard breeding.
For this pregnancy, we are here to help and answer your questions. But at least neuter your male because he can get her pregnant as little as a week or two after giving birth. He needs to be completely seperated from her when she is ready to give birth until the babies are older. They need to stay with the mother until they are 10-12 weeks old.By 4 -5 months, they can also become pregnant. Good luck.