US Graduate School without subject GRE
I'm afraid there's not really a lot you can do. Your best bet is, as always, to contact the departments you are interested in attending, and explain your situation to them. You'll need to have a very convincing reason why you weren't able to take the GRE subject test, and would need a waiver. They may be willing to make an exception; they may not.

Beyond that, I'm not sure what else you can do; the policies and deadlines are all well-known and published, and the departments are not required to give you special treatment.