E-filed I140 question

I e-filed I-140 on last Friday morning, and got the receipt number immediately. The supporting information package was sent on last Friday by express mail, received by the USCIS service center on Saturday.  When I tried to check the case status on line today, it said the receipt number is invalid. Is this normal?

If yes, how long it normally takes for the receipt number to become valid on USCIS website?

Thanks a lot for your help