I felt it too, as did one of my kids. The two who were outdoors didn't notice it, although I might have, since I lived in CA and am attuned to what they feel like even when you can't see them.
I have facebook friends from all over, and it was felt all the way from Michigan to North Carolina.
One of my friends in the Alexandria, VA/ DC area said they may be evacuating the Capitol and Pentagon, and that cell service there is out.
Prayers going up for everyone's safety and that there's no panic. This part of the country doesn't get many earthquakes.