The risk is very low if you take proper precautions.
Wear gloves/mask when changing the litter box.
Keep your pets vaccines, flea treaments and worming up to date.
Keep the litter box clean (don't let it build up).
Wash your hands after handling your pet.
Wash your hands before eating.
Wash all food prep areas before use (and after).
You are more likely to get toxoplasmosis from dogs than cats.
If you have had a dog/cat for any length of time chances are you already had toxoplasmosis anyway.
You can have a blood test done to check for toxoplasmosis anti-bodies but this is only worthwhile if you had a check done before you got pregnant, as it only shows you have the antibodies not when you got toxoplasmosis.
If you follow basic hygiene rules the chances of getting it are so low. It's a bit like saying don't go out in the street in case you get hit by a car.