11.5 is high at that time. It is high at any time. What did you eat and what was your pre meal reading and why test ten minutes after eating? Did you test again after washing your hands to check for a dud strip or contaminated fingers?
My spike doesn't start for a while after eating. I am inclined to think that you were pretty high before eating and probably got even higher when the meal took effect. In any case, 11.5 is not low since it would bust you at the surgery if it was taken as a random reading.