Hi Puppies,
There is a risk but the risk is with the faeces so as others have said you should avoid changing the litter tray or change it using gloves. The other high risks area is in the garden - eg. vegie patches as yours and other cats may have used it to defaecate as well. Use gloves for this as well. If you have had cats for a while you may very well be immune. When I was pregnant, I was still working at a vet clinic. I probably have some immunity from before but just made sure that my hygiene was good and I used gloves, washed my hands etc. I certainly wouldnt suggest rehoming your cat although I generally wouldnt recommend pregnancy as a time to get a new animal. HTH.