help - what would you do?

[harkharkhark]

DS's nursery has gone from 2 cases of chicken pox on Tuesday to 17 by Friday.
He goes a couple of times a week. Past three days he's had very runny nose, very bad cough, grumpy and aimless (wanders around grumpily). My gut is that CP is on its way, but I've no idea of knowing until spots appear. It could be yet another nursery bug...

Today we are meant to be having a big birthday family bash for him.

My mum has never had CP. She's elderly. Nor has my 10 month old niece.
My mum says it's my decision and she would still come (although I think she's nervous, but she's desperate to see him, they live a couple of hours away).

But I don't know whether to go ahead. I understand this is the most infectious stage and that worries me.

Then again, I don't want to be a worry well over nothing.

AAGH!

If he's got no spots then I would go ahead with the party but let people know so that they can avoid it if they're worried IYSWIM.

He could just as easily be brewing CP if he felt well and pass it on to people before he had any spots

Yes, that's what I've done but it doesn't help my quandary!

Are you sure that there will not be anyone there in the early stages of pregnancy. It is another consideration. I was terrified of coming into contact when pregnant as a good friend had lost her baby this way and I myself had never had it. .