I am flying into ORD from IAD this Wednesday, en route to YEG, on United/United Express. I have 40 minutes to make the connection and have no idea how easy or difficult it may be. Anyone know which terminal I am likely to arrive in and then fly back out of on this itinerary? Will I have to re-screen my carry on luggage at any point? I'm preparing myself for the worst, but I figure if I have as much info as possible ahead of time I'll be better off. Thank you!