WONKY READINGS

2.9 was a spurious reading - perhaps with water on the hands. Trust the two higher readings.

I suggest that you ignore peculiar readings. Finger-prick tests are great for giving you a rough estimate of your true BG, but they aren't that accurate. Not only are domestic meters not up to the standards of lab equipment, but the tiny blood sample taken means that infinitesimal amounts of contamination can throw it off. A tiny bit of soap or water can give you a low reading, and food particles too small to be seen can give you a high reading. This is why doctors use blood samples taken from a vein and analysed using lab equipment - that is vastly more accurate. However, if you are careful you can increase the accuracy of your own testing. Before I test, after washing my hands I rinse the finger that I am going to prick again and dry it thoroughly on a clean microfiber cloth that I keep for the purpose. This seems to cause fewer duff figures.

If you are concerned about your meter (and they can get damaged - dropping it could do it), then phone up the manufacturer. Most of them will send you a bottle of test solution, that contains a known value of glucose, that you can check it with.