Should we go to the er or wait?

My son is 17 months old. He's had lots of yellow/green eye goop for 2 days. I called his pediatrician today, but they can't get him in until monday. We're supposed to be hosting easter at our house sunday. I don't know if I should wait until monday when his pediatrician can see him or go to the er. his eye is slightly pinkish, so I think it may be pink eye. I also have 2 older kids and, like I said, we're hosting easter in 2 days and I don't want this to spread to everyone. I'm just not sure if it's worth an er trip our if we should tell the family to do easter some place else while we stay home and wait til monday when his doctor can see him.