It's good that you are thinking about this now! First, make sure that only your husband has access to the meds--have him lock them up if need be. You need to not have any access to them except through him. Have him give you only the bare minimum you need for pain relief, but try to go without or use other meds first, like tylenol. Once you are through the worst of the pain have your husband FLUSH them down the toilet.
Everyone is different, but if you use the bare minimum for the shortest amount of time you will likely not have withdrawals or only very mild ones. Drink lots of water and just keep your mind on your recovery. And come here to SR lots, every time you get a craving or feel worried.
I was afraid I was going to relapse a few weeks ago, around physical pain issues. I came here tons, was honest, and now I am in a totally different place. You don't have to relapse! If you're worried just let that fear motivate you to stay clean. You can do it!