I brought the ORD-IAD-LHR-IAD-ORD fare mistake $346 special a few months ago. I was hoping to skip the last leg cause I have an appointment now in Washington. What options do I have?

1. Ask checkin at LHR only to tag the bag to IAD
2. Get reservations to alter my ticket
3. Fly to ORD then fly back to IAD

If anybody can tell me exactly what happens when you arrive at IAD? Like do they have somebody checking the bag tags then directing you into a line or do the IAD bags get directed somewhere else?


Thanks