It depends on the luck you have….

10 min walk from baggage to metro station at dulles, enter with ticket, up to platform

0-20 min wait for next train

45 min to Roslyn. At am/ pm rush hr you can have a 5-10 min delay due to load/unload and more trains on track)

0-20 min wait for blue line to Roslyn. You go from upstairs to down stairs to get to DCA. Bottom is out of dc direction.

10-15 min ride to DCA.
American check will be the back of the train direction. Delta/ United to the front. A
Alaska, jet blue inn-the middle. Southwest and frontier in terminal 1..an additional 7 min walk.

at this time yellow line is not operating so there is a double load of blue line routes. One is normal blue line of largo- Franconia. Yellow line substitute is vblue line from Huntington to new Carrollton

ehrn yellow line is running……you could stay on silver line to lenfant thrn upstairs to yellow line to Huntington thrn take thst to DCA. It can be longer but it coukd be about the same if you just missed connection from blue.