You will have been sent the Applicant Copy of the Enhanced CRB check. Ofsted will get their own copy for their records. It may take a few days for Ofsted's copy to arrive and get to the person(s) dealing with your application.
However, next week, call Ofsted and speak with the person(s) dealing with your application to check what is still outstanding. Tell them that your CRB has come through if they don't already have that, so that they can hunt through their post!
With luck you will be nearly there. You never know, you may be registered in time for the start of term.
Once you have paid your fee (I would suggest doing payment over the phone using a debit card or something similar - note the Payment Reference), contact Ofsted and tell the person dealing with your application that you have made payment and give them the Payment Reference. They can then check that payment has gone through and get your Certificate issued. Seeing that it's now the weekend, if payment goes through say on Monday, I would expect you to have certificate by Thursday at the latest, all being well.
You CAN NOT care for children until your certificate arrives, and you have insurance cover.
So you can start getting things in motion - for example, you can confirm with your insurers that you wish for insurance cover to start (if they need the registration reference number, use the one that is on your recommendation letter). Confirm with your car insurers (if you are using your car for transporting minded children) that you want your Business Use cover to start. Call the parents of children on your waiting list, to tell them the great news, etc.
Nice to hear that things are going along so quickly.