One of the best ways to determine the most fertile period is to pay attention to your body and learn to detect the signs of your forthcoming ovulation. Changes in your cervical mucus. As your cycle continues the amount of cervical mucus increases and its consistency changes. The increased amount and the changes in consistency portray the increased amounts of estrogens in the body. A woman is considered most fertile when the cervical mucus appears clear, stretchy and like egg white in consistency. The role of the cervical mucus is to nourish, protect and accelerate the spermatozoa in their direction towards the womb and the fallopian tubes until they meet the oocyte. Measurement of basal temperature. After ovulation, the temperature of a woman rises 0,5 to 1,6 degrees Celsius. This change in temperature may not be perceptible immediately, but can be detected using a thermometer. This occurs because the release of an oocyte stimulates the production of a hormone called progesterone that causes the increase in the basal temperature of the body. A woman is more fertile 2-3 days before the increase in her basal body temperature.