It's horrible when you can't trust someone anymore. Yes, in this case, I would do the same. Change your contract to either 1. limited number of sick days at discounted or no charge, the rest are paid. or 2. pay for the spot!

You shouldn't have to question if a child is sick.

The other issue is ... if a child is sick enough to be at home I feel I need to let the other daycare parents know so if it's something serious they can look for signs and symptoms. Whenever a parent calls their child in sick I ask for what symptoms they have so I can be aware for my own kids and the rest of the daycare kids.

Maybe start asking those questions for the safety and health of the rest of the daycare.