Each cycle, one of your ovaries releases an egg; this process is known as ovulation. Your body produces more estrogen in the days leading up to the luteinizing hormone spike (LH). By making the womb lining thicker, estrogen aids in the preparation of the body for ovulation. It is also responsible for the development of cervical mucus that is favorable to sperm. The increase in estrogen signals the beginning of your high fertility window, which might last four days or longer. The LH surge, which takes place 24-36 hours before you release an egg, falls on your most fertile days. Given that sperm can live for five days, understanding your high fertility and peak fertility days through hormone testing might help you schedule sexual activity to maximise your chance of becoming pregnant. Ovulation tests can be useful in this situation since they can identify the elevation in these hormones in your urine. Ovulation tests eliminate the guesswork involved in determining your most fertile period because each woman is unique and because menstrual cycles can differ from cycle to cycle within you as well as between women.