Hey happyhope!!!
I have had 2 discectomies, and wasn't allowed to drive until after 6 weeks, and was able to do so comfortably.
Your physio will tell you to make sure you are in a comfortable position, and start with short journeys only.
But....As I have been through it twice, i would say there is no way i would have driven after only 4 weeks. I got incredibly bored, but toughed it out for the next 2!!! As well, if you are on any medication, better check the label in case it says anything about drowsiness.
Only 2 more weeks, you can do it!!!