The figure ABOVE shows a typical mucus cycle going from minimal, progressing to stretchy cloudy, then to peak and back again to tacky cloudy type mucus. 

Mucus cycles will vary from women to women and from cycle to cycle. 

Beginning fertile mucus
Fig. 7:  Beginning fertile mucus = Low Fertility

Figure 7 shows how cervical mucus might look at the beginning of the mucus cycle (the beginning of the fertile phase).  When a woman observes mucus she can feel for the sensation and observe its characteristics.  Many women observe cervical mucus by finger testing, lifting mucus off of a tissue and observing it at eye level between the finger and thumb. Early cervical mucus usually feels moist or sticky, and appears scant, thick, minimal, white, and holds its shape.  When a woman observes this type of mucus or has no mucus and a dry sensation, she is at LOW fertility.

Fig. 8: Transitional cervical mucus = High Fertility

As the cycle progresses and more estrogen is secreted by the growing follicle, the mucus increases in amount, becomes thinner, cloudy, slightly stretchy. The texture of the mucus might also change from moist and sticky to wet.  When mucus is observed with these characteristics it is considered a sign of HIGH fertility. 

Fig. 9:  Peak fertile mucus = Peak Fertility

The peak of fertility during the menstrual cycle occurs when peak type mucus is present.  Mucus at this time has a very slippery (lubricative) sensation. It appears transparent, clear, is very stretchy and looks similar to raw egg white.  At the peak of fertility, cervical mucus is very profuse and literally pours out of the cervix over a 24-hour period. Sometimes the mucus is so watery that there is no mucus to pick up, and the women will only notice a very wet, slippery sensation.

The PEAK DAY of cervical mucus: The last day of any mucus that is clear (transparent), stretchy, and/or has the sensation of slippery is considered the peak of cervical mucus and the Peak day. After the Peak day there is an obvious change to sticky, tacky, cloudy type mucus or to dry (i.e., no mucus appears at the vulva, and there is a dry sensation).  Therefore, the Peak day will only be known retrospectively! Fertility is High for 3 full days after the Peak day of cervical mucus.