I had the very same pain once and went to my Dr. who said the very same thing as yours did just from a physical exam ~ no redness nor swelling etc ~ no DVT.
In about half of all cases, deep vein thrombosis occurs without any noticeable symptoms. If you still have the pain and any other cause for concern do talk with your Dr. re further testing.
Remember many things can cause pain in your leg so try not to get caught up in the "what if?" thinking.
As SC mentioned there are many other conditions that can cause an elevated d-dimer.
Good luck and remember to take a deep breath and just be in the moment.
Kindly,
Kitt