Sounds to me like the doe ran into the woods and stopped to assess the situation. She probably clotted up a little and couldve bolted once alerted by you tracking her. Clotting and then taking off quickly will leave little in way of a blood trail. As said she also couldve backtracked her trail and veered off-grid searching for a body is all thats left now. Was there a puddle of blood at your last spot of blood???