I started charting mid cycle last month. I was using a really good thermometer that I trusted, of course it broke shortly after starting to record temps. Bought a new one and it seemed like it was recording kinda high. It was a cheap regular thermometer and took like 5 secs to record. I began to think it wasn't accurate and bought another one. When I compared the two the cheap one was an entire degree off. Now I'm concerned my chart is all off because of this thermometer. Has anyone changed thermometer mid cycle? What should I do?  Pics of their thermometers below: