Chicken pox advice!

My partners brother, wife and two kids visited my partners parents house yesterday. His children have chicken pox which isn't fair they shouldn't of gone round there!

I've told my partner we are not visiting his parents house for at least 3/4 days because the kids played with the toys etc which could spread the chicken pox. I'm pregnant also so no way am I risking getting that or my young children!

My mother in law is moaning saying it's safe to come round but I would rather be extra safe and leave it at least 3/4 days from when they came round!

I don't know the risks of chicken pox in pregnancy but I can imagine it's not ideal! I also have a 3 and 1 year old.

Am I over reacting or would some of you agree leaving some time to visit is the best thing?