First, your little one should be fine...ASSUMING that you do not allow it into the bathroom which your husband is using and that both you and your husband are scrupulous about hand washing.
It is not unusual that your husband is not feeling any side effects from the first treatment. It is, however, common for the side effects to increase with additional treatments. The purpose of the BCG is for it to kick up the immune system and it takes a while for this to happen.
Drinking fluids is a good idea, but he will be OK anyway. If he is fond of some particular drink, just be sure you have it on hand and offer it to him!
Sara Abbe