how to check if my H1 petition extension got filed under premium?

[daemon]

My employer had filed my extension last month for my petition that expires next month. Now they are saying they have changed to premium. How do I check if my extension has changed to premium?

I have the older receipt number. Does the receipt number change? Will they file a new petition disabling my earlier one or will they amend the existing one? In either case will it change the original petition receipt number that I have? USCIS only tells me the status of my current petition. It doesn't tell me if it was filed in premium or not.