It says "start monitoring your cervical fluid"

Sheera
What does this statement suppose to mean? What are the ways to do it right? Looking forward for an answer.
My name is Kaye and this is my first day in using the <a href="https://play.google.com/store/apps/details?id=com.glow.android">glow app</a>. My purpose in having this is to track my cycle.