i'm not sure if the change in blood sugar you experienced is a sign but it might simply be a result of what you ate. did you eat the same amount of carbohydrates at both meals? if you had more carbohydrates on sunday that would explain the higher levels. recommended blood glucose levels 2 hours after eating is less than 140 mg/dl for people 50 or younger; less than 150 mg/dl for people ages 50-60 and less than 160 mg/dl for people over 60. for more on measuring blood glucose levels with diabetes see this webmd article.
i use the two hour after meal method to check my sugar. sunday's reading was 246 monday's was 116. is this swing a sign?