How can I use my temperature to know if I'm ovulating?

While your waking temperature is lower before ovulation (97 to 97.7 degrees), it rises after ovulation (97.8). The rise typically happens a day after ovulation (because of progesterone, which induces heat). You can get a sense of when you're ovulating by taking your temperature first thing after waking, then plotting the numbers to the tenth of a degree. Ovulation has occurred when you see a more dramatic shift than the day-to-day fluctuations that happen during the rest of your cycle. That will give you an idea of which day in your cycle typically is your ovulation day.