that depends. have you had more than one visit to his office this month?
if anything, you could call and at least try. just call and be like "I'm out of my medication, is there any way I could get the doctor to write up a script and I can come pick it up". if they say yes, then just go and there shoudln't be a co-pay. but your other option is that they say no. thats it.
but if you do that, make sure you really are supposed to be out of your medication before asking. they keep records of the last time you had something filled, and if you go in asking and saying you're already out before you actually are supposed to be. its a red flag.
I just went through this today actually. got my script of ms contin's upped to 3 times a day instead of just 2. so I go to walgreens to get it filled. my insurance company won't pay for it until sunday because it hasn't been a full month on my last one (even though I"m out, and I"m not supposd to be). so needless to say, I walked out of walgreens today NOT a happy camper. but, at least I know I'll have my meds on sunday, bright and fuckin' early!