I can understand how you are feeling. He is contagious until 5 days pass from occurrence on the first blister. The incubation periode is 14 to 21 days. Your niece may only start blisters in 2 weeks. My daughter is 10 months and is completly covered with chicken pox. It has been a very rough 2 nights. She is very upset and ABSOLUTELY does not want to sleep. Do you have any suggestions and helping her sleep.