I have a fasting blood glucose level of 196, then ate a bowl of vegetables and went for a walk and an hour later had a reading of 182. I thought my reading would go up, not down. Another hour later the reading was 185, and another hour later the reading was 156. I have not been diagnosed with diabetes, but these readings seem very unusual to me. I had issues with thirst and frequent urination for a few days, but they have gone away at least for now. Am I already diabetic?