Hi Elmbabies and welcome to the boards...to answer your question it would depend on what the doctor has given you to take...some medicines like lyrica, savella, and cymbalta take up to a month before you feel any difference. Others like regular pain medications will work right away to take away the worst of the pain, but none take away the pain completely. Most will make brain fog worse...If your pain is the same after an acceptable amount of time, depending on the medication(s) you are taking, then you can feel free to notify your doctor if the medication doesn't seem to be working...So if you are on regular pain medications, a few days to a week max, then call your doctor if they don't seem to be working. If you're taking a drug like the ones listed above, I would wait a month to see if it will work or not. Also just a note, if you are having any serious side effects from anything the doctor prescribed, call your doctor right away, don't wait.
Great to have you on board...Gentle hugs