Menstruation will occur within two weeks. The woman is not fertile if menstruation occurs less than 11 days following the Peak. The interval of 11 to 16 days from Peak to menstruation will return subsequently, signifying fertility. If ovulation does not precede a bleeding episode, the bleeding cannot be classified as menstruation. If the woman identifies a Peak Day she now applies the Peak Rule .
Menstruation always follows ovulation.
Avoid intercourse during days of heavy menstrual bleeding. The following example charts use International Charting Symbols . The BIP is her own unchanging pattern as she observes it, with her unchanging description. Every woman is an individual and describes a discharge in her own way. She should not evaluate the discharge by the experience of another woman or by pictures of an isolated specimen.