So this is my second month charting. The first month everything with my temps made sense. Didn't have any issues. This month my temps seem to change a lot even if taken around the same time. I'm wondering if something is wrong with my thermometer. For example. I took my BBT when I woke up it was 97.5, I then re-took it right after and it was 97.16. I then took it again right before I got out of bed which was about half an hour later and it was 97.23. I'm keeping in the same spot. The difference in time was about half an hour. This isn't the first time this has happened this month with 2 or 3 very different temps. I'm going crazy trying to figure O out. I was the tip every day, is it possible it's water damaged?