With out a microscope and some specialized scientific training, it is not possible to know if the eggs were fertile or infertile. What really matters though is do I get some baby chicks or not. It is generally the experience of most that on average you will get 30 to 50 percent hatch from shipped eggs. I have had eggs that hatched 90% and those that gave me zero. It may or may not be the suppliers fault and that can be a difficult and often unproductive discussion as there are just too many variables.
My experience with bob whites has been 60-80% with shipped eggs, but I have only dealt with 2 suppliers. My experience with chukar has been more in the 30% range with shipped eggs so you are doing better than I have.
I live in Alaska so they all have to come a long way. Mallard eggs have shipped well here, but pheasant just are not worth shipping in here. I buy day old chicks and save the frustration, that and hatch what few local eggs I can find.
It is always best if you can buy from a local source where you control the transportation and conditions and with whom you are familiar. Baring that it is a bit of trial and error. If you buy two or three batches from a supplier and they have a poor hatch rate and you have good luck with another, the choice is obvious. Usually there are people who buy from a supplier who have good experiences and those who buy and don't do so well, but they do well with another.
That being said, I think it is a miracle when I get any of them to hatch after considering what all they have been through and the many variables and mistakes I make in the process. Good luck and enjoy.