Do I need to buy anything in particular for my pregnant cat?

Not really. The care for a pregnant cat is virtually the same as any other adult cat. One thing that I like to do, however, is to switch the moms-to-be over to kitten food. Yes, of course, I do understand I'm talking about feeding an adult animal kitten food, but the reason why is because kitten foods tend to be higher in fat, higher in protein, higher in calcium. These are all things that they're going to need when they're producing a litter of kittens and very shortly thereafter in order to produce plenty of milk. They're going to need some of those increased nutrients. I typically recommend that pregnant cats eat the kitten food until the litter is weaned.

One or two weeks before your cat is due to give birth, start transitioning them over to kitten food to provide higher calorie and calcium content to help them produce milk. This will help them keep up with their calorie needs when those kittens are nursing. Otherwise, you can use a cardboard box with an opening on one side, a couple of clean old towels, a food bowl, and a water bowl. Cats are often excellent mothers and don't require much.