The production of cervical mucus is stimulated by:

Thin copious cervical mucus in the mid cycle is indication of ovulation and is maximum on the 14th day of cycle. Intercourse in this time is more likely to result in a pregnancy as the sperms have easier access to the tube as the cervical mucus is thin which is facultative for easy sperm travel to the uterus. The first half of the menstrual cycle is characterised by increased estradiol levels and an increased amount of cervical mucous. Estradiol also makes it more thin and watery to allow sperm penetration. in the second half of menstrual cycle, which is progesterone dominant, cervical mucous becomes scanty, thick and opaque.