emergency overnight childcare

[Princess]

Can anyone recommend a reputable firm who are able to provide us with night nanny (who more than likely won't need to do anything as my son is 18 months and generally sleeps really well) or very capable CRB babysitter for the next 8 nights and possibly a day or two at short notice?!

With baby number 2 due in 13 days, we have cover in place for all overnight eventualities in 9 days time but nothing for now.

Having had a few 'twinges' this weekend and a precipitous labour with my first, we would feel a lot better if we had someone with us overnight as we fear there won't be time to ring around our list of friends, get my son up and drop him off before baby arrives!

Thanks in advance

Px