Welcome to you, and good luck with the testing!
I was told at the hospital, as long as I was off the pain killers for a couple of days I was fine to drive - no problem! Since I had never had surgery before, I took them at their word - wrong move!
Our surgery was on a Tuesday, we were home on Saturday, and the next Wednesday I decided I felt I was up to driving the five straight blocks to the pharmacy to pick up a prescription. We had a myriad of friends and family that were helping, but I really wanted to do this myself. As soon as I started out, I knew I had no business behind the wheel. I think it was most likely the residual effects of the anesthetic. I seemed to have major problems concentrating and coordinating - things that you normally would do naturally when driving such as looking both ways, watching the light, coordinating brake and gas, etc.
After that experience, I waited about another week and then drove my husband to dialysis to visit his friends and the nurses there. By that time, everything "worked" a lot better and I felt more comfortable behind the wheel.
Another thing to keep in mind is that it was still pretty uncomfortable to get in and out of the vehicle, and, heaven forbid, you have to turn your body or stop suddenly! Ouch! You will find that people will be standing in line to help you. If you can get a driver for the first week or so, by all means take advantage of it. They will feel useful, and it will certainly help you out.
Glad to have you here, and keep us posted on your progress!