Vaginal mucus is a natural substance occurring within the vagina, particularly the cervix, that maintains a certain level of moisture at all times.
The volume, colour, and consistency of vaginal mucus changes according to the period of the menstrual cycle. Both the chemical make-up and the physical consistency (viscosity) change during this time. A slippery, clear, egg white-like consistency usually indicates that the woman is ovulating. Relative dryness usually indicates an infertile point in the menstrual cycle.
Menstrual cycle is the cycle of changes that occurs in the uterus and ovary for the purpose of sexual reproduction. It is essential for the production of eggs and for the preparation of the uterus for pregnancy. The menstrual cycle occurs only in fertile female humans and other female primates.
In humans, the length of a menstrual cycle varies greatly among women (ranging from 25 to 35 days), with 28 days designated as the average length. Each cycle can be divided into three phases based on events in the ovary (ovarian cycle) or in the uterus (uterine cycle). The ovarian cycle consists of the follicular phase, ovulation, and luteal phase whereas the uterine cycle is divided into menstruation, proliferative phase, and secretory phase. Both cycles are controlled by the endocrine system and the normal hormonal changes that occur can be interfered with using hormonal contraception to prevent reproduction.