Does it matter how high the temperature is? Or just that it spikes at a certain time each month, hopefully meaning that you are ovulating. My spikes (over the last 2 cycles) have never gone higher than 98.1. I was just put on synthroid though too for a high TSh (hypothyroid), so this could be part of it too. Just wondering if the actual temperature has an effect.
No there is no set temperature - it varies from woman to woman. What matters is there is a sustained shift upwards in temperature - I think most of the charting softwares out there use three days of sustained upper temperatures to pinpoint ovulation. The temperature rises because of hormonal activity. After ovulation, the temperatures usually remain elevated until you start AF. If you AF is late and your temps are still elevated, that can be an indication you are pregnant.