Regular use of normal household cleaners hasn't been shown to harm a developing baby. Still, it's a good idea to stay away from oven cleaners that emit strong fumes in a contained space. And, pregnant or not, don't mix chemicals such as ammonia and bleach because the combination can produce toxic fumes.
When cleaning, avoid inhaling any strong, caustic fumes. Wear protective gloves to avoid absorbing any chemicals through your skin. You might also consider switching to cleaners such as vinegar and baking soda or other products that don't contain any harsh, toxic chemicals.