Am I allowed to pick up my FedEx package at their locoation?

I have a package on the way from FedEx that's at the FedEx place waiting to be shipped. On my tracking, though, it says that they're not shipping today because it's not due for shipment. Problem is it's time-sensitive and if I don't get it today it could cost me a great sum of money. Would I be allowed to go down to a FedEx office and pick it up, or do I have to wait until the day after tomorrow when it's too late and it's ruined?