Hi. When you say you suffered a concussion, what do you mean exactly? Did you black out or lose consciousness? Have you had headaches, vomiting or double vision? Your GP is saying something very significant if you had bruising to the brain - you would have had a CT scan of your brain to confirm this and most likely been in hospital for a few days. If you did indeed have bruising to the brain then I would suggest a long haul flight in two weeks is certainly not a safe idea. You would need to inform your airline and insurance company about your recent injury and they would be able to advise you further with regards to their own policy on this type of injury. If you did not undergo a CT scan of your brain then you would need to clarify your diagnosis with your GP, who could then advise you further.