My son will be 18 months old later this month and we would like to begin his potty training early as you advocate. However, I am pregnant with another son due in January. They will be 21 months apart. "Everyone" tells me I should wait to potty train my oldest until after the baby comes and he gets "used" to him. If I don't wait, they say, he will almost certainly revert. Can you offer any insight or advice on this matter?