It may take as long as 1 month, especially since the August class is just underway and the committee has been busy getting that class going.
I would say, wait for about 3-4 weeks and if you still do not hear anything, call SGU and inquire nicely about your application's status.
I send in my application for January MORE than 1 month ago, and was interviewed about 3-4 weeks ago, and have not yet heard anything about an accepteance/rejection. But, they WILL let you know if you anything does happen...don't worry.