As per my law firm, USCIS are randomly sending confirmation receipt for advance degree quota and regular quota. In that case they are processing 85,000 at once and even if you assume that the Premium processing are 40% of them that will be almost 35,000 applications. So, as per him we will need to wait atleast till next friday before we start panicing as the USCIS has 15 days starting from 14th april that will be upto 29th. Today is only 18th so don't panic. Enjoy your weekend.