Considered a natural birth control method, the cervical mucus method is a low-cost way of monitoring the days you ovulate by self-tracking daily cervical mucus secretions. This fertility-awareness-based method helps you determine which days you are fertile, and consequently, know when the best time is to have unprotected sex to prevent pregnancy.

"Cervical mucus is a fluid secreted by glands located around the cervix. The consistency and amount of this mucus changes along with hormonal changes throughout the reproductive cycle," said Jessica Shepherd, M.D., an OB-GYN, chief medical officer of Verywell Health.

The changes in appearance, texture and odor of the mucus can help determine when a woman is about to ovulate, allowing her to make better-informed decisions as to whether or not to have unprotected vaginal sex.

"A vaginal discharge resembling raw egg whites signals that you're most likely ovulating and is the best time to have sex