Total Carbs - Fiber?

Patricia
Ok so I was doing some reading and noticed that fiber, despite being a carb, doesn't raise your glucose levels. Some things I read said you can subtract fiber from a meals total carbs for that reason. So say I'm allowed 45 carbs for lunch and my meal comes out to 37 Total Carbohydrates, but 5 of those are fiber. Am I counting that meal as being 37 carbs, or 32? I purchased some whole wheat tortillas that say right on the packaging that you can subtract the fiber, which puts the tortillas at very low carb status. I'm just trying to get this all straight in my head so I know if I'm actually getting enough or if, in some instances, I can/need to add more!