How long have you been doing Low Carb? In the early stages our bodies need time to adjust to it, and during this time we can suffer Liver Dumps caused by our bodies thinking we are starving and reacting to boost bgl. If we persevere, then our bodies start burning fat instead, and we start to lose the stored reserves in our liver, and this reduces the liver dumps as the liver stores empty. Then apparently we get the LC Flu, which occurs as our bodies take up fat burning big time, and once we acclimatise to that, then all is hunky dory, and our bgl should steady out.
For me, it has taken 3 months of LC to get to a more stable position, and now I am regularly hitting inside the 4 to 6 mmol/L range.
Other things that can be happening, I noted that a change of test strip paks can give a rise (or drop) in bgl averages by up to 2 mmol/L Sometimes a cold or infection can affect readings. Make sure you wash and thoroughly dry your hands when taking readings. Have you changed medications recently? Cough mixture? suffering increased stress? Change of drinking habits?