Tracking your basal body temperature (BBT) to determine ovulation is an old method based on a slight rise in body temperature after ovulation. This temperature shift happens due to progesterone production by the corpus luteum—the structure formed from the follicle after releasing the egg.  

However, this method has several limitations:  

- Temperature must be taken every morning at the same time, before getting out of bed.  

- It only confirms ovulation after it has already happened, meaning it cannot be used to time intercourse for conception.  

- It does not provide any information on egg quality or fertility potential.  

Today, we know that tracking temperature is unnecessary to confirm regular ovulation. Having regular menstrual cycles is a strong indicator of normal ovulation. If needed, a blood test measuring progesterone between days 20 and 23 of the cycle can confirm ovulation—levels above 3 ng/mL indicate that ovulation has occurred.