Like someone else has already said, ask your doctor, or preferably, a physical therapist and your doctor. If your doctor already told you to wait about four weeks before training the upper body, then I'd wait four weeks before doing anything upper body. We might know more about bodybuilding than most doctors out there, but most doctors know their stuff when it comes to what they do. So if the doctor who's performing the surgery on you has given you this advice, then it's best to take it.
However, I understand that you're wanting to hear from others who have personal experiences with this situation, and that's completely understandable. But I'd still talk to a doctor and physical therapist, taking their advice over anyone's advice on these boards. No offense to anyone on these boards, but that's just the safest way to play it.
Good luck with everything, buddy!
