I don't know where you are getting the "after hours" part.
What I was talking about is that you don't know what you doctor is going to have you take for some illness before you get sick. So. . . you can't stock up ahead of time.
I don't understand your last paragraph.
None of my doctor told me to use Walgreen or CVS.
My last paragraph in the quote above has nothing to do about which pharmacy to fill the prescription at. But that you can't know what your doctor is going to prescribe for any given illness before you get sick.