I wake up every morning at 645 to take my temp. My temps usually fluctuate quite a bit, especially in the beginning of my cycle, except for this month. I use a bbt thermometer to the 100th degree. To make sure my thermometer is working properly I have also taken my temp at different times of the day and again a few minutes after the very first. This past month was the first month I was put on progesterone. Could this be because my hormones are balancing? Do I need a new thermometer?