CSA - how long

[mycats]

I knwo I might get a few cynical laughs here but -
My ex is signing on (he is a waster) and my son is now 11 years old and I have never had a penny from him.
I recently went on to income support over the summer holidays from collage so the CSA got in touch.
They said that, if he was singing on I would get �5 a week from him (woo hoo what will I spend the riches on lol) anyway, I asked for it to be payed every four weeks and I am just gonna put it straight into my sons savings account.
Does anyone know how long it will take for it to start coming through?
thanks