If you have a GA it's 6 weeks, hospital told me to allow 2 weeks for physical recovery and after that drive when I felt fit.. I checked with insurance company who said to go with advice from hospital xx
The issue is insurance, so always check with them first - you don't want to go driving, thinking you are ok, and end up not covered by your insurance should something happen. I had a pretty rough recovery with my first, so really didn't feel up to driving for a long time anyway.