I think it's possible, because the doctors test are meant when you miss your period. These can detect early pregnancy. What suggest is get a dollar tree test, see what that says. If you a really faint positive, just wait until it gets darker. Because maybe the doctor didn't see the faint line. Also how long was it when you went to the doctor.
Yes I did well I actually work at night and I didn't use the restroom till I got home in the morning from work ..which was 7am would that make a difference ?