We started our Dexcom yesterday and I think the rep was surprised by how much I knew already about how to use it. I THANK ALL OF YOU HERE for your tips and tricks that you all post. I have learned a lot. After we started last night we were amazed that it was only 1 point off from the meter reading. But about 4 hours later it was 100 points off from the meter. is this normal? We recalibrated at that point. This morning when i woke up i looked to see what my son was and Dex said 92, meter was 150. Again, is this the type if accuracy we are to expect cause i'm not impressed.