Please take a moment and update your account profile. If you have an updated account profile with basic information on why you are on Air Warriors it will help other people respond to your posts. How do you update your profile you ask?
If you are getting E-3 pay (for your lewisville zip) it should be 1320 a month with dependent, 990 without, so sounds like the 2100 is the back pay. http://www.defensetravel.dod.mil/perdiem/bah.html has easy input for this
That's the link I couldn't find, thanks! The standard pay sheets don't go into the detail about BAH or BAS, but I knew there was something else I saw that dealt with it.