I just started using Bumgenius 4.0 diapers yesterday and my 5 month old son woke up with a rash on the front of his pelvis this morning. He nurses once during the night and I don't change his diaper because it wakes him up too much. We didn't have any leaks in the morning just the rash. Could it be from being too wet all night? Can I use some cornstarch to keep him more dry?