I am 36 + 2 weeks and my son has got chickenpox, please read

I'm 36 + 2 days and my son has just got chickenpox, I have had chicken poxs twice, so I'm certain I definitely won't get it again but can my unborn baby? Is there any risk to my unborn baby if I've already got immunity? I'm a nervous reck I've tried contacting my midwife but had no answer yet going to try again in the morning and also call up my gp.