"Wasted my time"

I was advised by my consultant to undergo a gluten challenge - I was not told of how long I needed to give in order for anything to show up in the blood test and as a result my results came back normal after I did the gluten challenge for 4 weeks instead of the 12 weeks I have found out by myself from the Coeliac websites. Had I have been told of how much time I needed to leave for the antibodies to show up I might have gotten somewhere. Instead I was told nothing. 9 months of my time has been wasted on something I could have been told at my appointment.