No I'm sure its neither of these payments as the Child Benefit is not until the first Tue of every month and the Childcare supplement is not until July as far as I know...
Just an update, this payment was in fact my FIS payment gone through. I cant believe that it only took less than 2 weeks as I was under the impression there was a few mths waiting list for it. I received my letter today from SW so I am delighted.