Changes In Mucus Right Before A Period Does Anyone Know What The Exact Changes In Cervical Mucus Should Be Throughout A Woman's Cycle?

Does anyone know what the exact changes in cervical mucus should be throughout a woman's cycle? - changes in mucus right before a period

So, I understand that during the cervical mucus of women with a substance such as the cream on a transparent material and must be elastic. But what happens before and after these 4 days? I had problems targeting exactly when I ovulate and can luteal phase extra long, so I wondered if anyone knows.