My DS was sick all the time for the first 6 months and so were we!! My GP, pediatrician, the daycare workers and friends with kids all told us that there would be 6-12 months of illnesses. It was really tough but he is hardly ever sick now. So it can happen to Sam, too. His immunity will build up and it is better now than when he starts school when he is older, imo.
I cannot count the benefits of learning to be with other kids, to get along with them, to interact with kids and adults, the life skills, such as, putting on jacket, tidying up toys, etc. I couldnt have done it myself! HTH