Cervical mucus is a fluid produced by the cervix, the lower part of the uterus. Its consistency and amount change throughout the menstrual cycle, influenced by hormones like estrogen and progesterone. This mucus plays a crucial role in fertility, helping sperm travel through the reproductive tract during ovulation. During ovulation, cervical mucus becomes clear, stretchy, and slippery, resembling raw egg whites. This change indicates a fertile window, making it easier for sperm to reach an egg. Outside of ovulation, the mucus is typically thicker and less abundant, which helps prevent sperm from entering the uterus.