Undercooked pork has the possibility of giving trichinosis, but this is rare nowadays. Even if pork is slightly undercooked it should be fine and I agree with a previous post that 40 minutes is plenty of time. Pork can still have pink parts when fully cooked, especially close to the bone or if it's the dark meat. It's most likely anxiety and you should be fine. If you ate too fast it could cause your symptoms, too, due to gas and indigestion.