Question simplifed : Can you still refill old low dose pain medication if you have 1 refill left on it even tho your doctor just prescribed a new script for the same med just a stronger dose?

Have been on vicodin 5-500 for a very long time for chronic pain and i guess it got to point either my pain was worse or my body was just too use to it. The pain was increasing every other year, this year it got to a point where i couldn't even walk. (I have been on low dose vic for 5 years.) Anyway my doc increased dose to 7.5 finally when I just broke down and explained this can't be good for me, because i was out of my 5-500 i went ahead and filled the new script, so happy it will be better on my liver. I also got another new script for ms contin and it's showing some improvement for me. I am wondering if later (after a month when i run out of this norco script if i can refill the old lower dose one and use it up or if I should just let it go to waste and stick to the new norco which is only 40 pills compared to 90 like i use to have.) Kinda pointless question maybe, am just curious if this is something people do or don't do? I think i'll probably not do this because the ms seems to be working ok right now, and I have only needed norco in the mornings for breakthru pain so I may start my day without terrible nagging pain. The only reason i'd use the old pills would be because there is more of them as well as the cost of the old ones is less than the new script, also they would last longer amount of days (i would guess up to a month and a half if my pain level continues to mellow out) so it would just save me money is all I see really. Sorry if this question is stupid I am just curious. I honestly don't think a person can refill old lower pain med after getting new script for higher pain med, cuz then they would just look like a junkie, not a money saver. Lol, am I right?