Caffeine really raises my BP too. Avoid it before going to see the doctor. Take your BP at home and show your MD that your blood pressure is normal most of the time and show him your log. Mine don't prescribe meds if you've got a touch of white coat syndrome.

BTW: Most nurses (and doctors) are really bad about taking blood pressure correctly. If they hurry you into it, don't let you sit for a while, don't support your arm properly, don't have it raised to the right height, it can mess up the reading. They also shouldn't be chatting away when they do it and you shouldn't be talking.