I was out last night and had my tea, had the correct insulin, 3 diet cokes, danced for 2 hours to blur and my BS was 13 which at the moment is very high for me as I very prone to having hypos as I am pregnant. The only thing I can think of is that may be a diet coke wasn't a diet coke. I must admit I am not good at telling the difference and was wondering is their anything on the market which you can use to dip in your drink to test for sugar, a bit like ketostix???