I personally would keep the cat in and get a box. The biggest cause for the bacteria is from cats that go outside. Indoor cats sometimes don't even carry the bacteria. If you do get scratched then wash immediately with soap and water. People can be immune to it and you can get it from lots of other things not just cats. Just be careful
My cat bit me, we somehow got fleas and I was attempting a flea bath because I didn't know if the flea medicine was safe during pregnancy, anyway it drew blood but I washed it immediately and I was covered in scratches. My ob told me it wasn't concerning unless the areas got red and inflamed. He told me he was more concerned about me doing the cat boxes. I'm a single mom and it's just me and my 5 year old daughter so I have to. But I just try to be smart about things. I wear gloves and masks for the cat boxes and wash my hands after touching or playing with them. I don't think you have to be too nervous if you use common sense.
Your cat may change too with the pregnancy. Mine has always been a lap cat that loves attention, but now he's protective of me. Which he used to go to the nearest lap. Maybe with you cat sensing the hormones. It won't scratch you like normal. Also can clip its nails if its an indoor cat.