Weep Screeds Help Channel water out of the space between your water barrier (Tyvek) and the stucco. If you don't have weep screeds, water is being trapped behind the stucco and is rotting your structural wood. That's right, the 2X4 stud that runs vertically in your wall is being rotted at the base. That same vertical 2X4 sits on a horizontal wood member called a floor plate. They are both fermenting in the water behind your stucco.
Here is what a weep screed looks like:
And it is fitted into the structure like this:
If you do not have a weep screed, you will want to have your walls checked for rot and damage. The absence of weep screeds is the fault of your builder and you should pursue them at the earliest possible opportunity.