Can I get prescription narcotics a week early?

I have a prescription for Lortab, for Degenerative Disc Disease, Sciatica, and the L4-L5 disc is herniated. My dr. and I are slowly lowering the dose b/c I've been on it for so long. But, it wasn't until this past two weeks that I've been *push* mowing my yard, so I've had to take more of the less powerful pain meds to relieve my pain. I have an apt. today for med checks and stuff, and I was wondering if I get the prescription if I can get it filled 8 days earlier than my last Rx?