I'm flying from Chicago to London Heathrow via Washington Dulles and am a bit worried about the whole thing. Is it easy for me to find where I'm going for my connection when I get off the plane? Its all with United airlines (both flights). Do I need to go through security again? What will happen to my suitcase? Do I have to re check it in? It's my first time flying on my own so it's all a bit scary! Please help?!