Would you allow your child to play with a child who has not been vaccinated?

Your son will probably be fine since he has been vaccinated. However, since you're pregnant, it would probably be best for you to avoid being around the unvaccinated children. I wouldn't risk it, if I were you. You're not supposed to be around children with the virus for Chicken Pox and various other things children are vaccinated for, and if they had a dormant virus in their system it probably wouldn't be good for your unborn children