The first indication of potential fertility will be a change from the Basic Infertile Pattern.  You will feel this changing sensation at the vulva, on the skin outside the vagina.  As the days pass you will notice that the mucus becomes thinner, clearer, and the sensation becomes wet and then slippery.  Women will use different words to describe this changing, developing pattern, but the mucus will always have a wet, slippery quality because of its chemical structure and composition, even when there is too little to see.

The fertile phase begins with the change from the BIP and, on average, develops for five to six days.  But even if it only lasts for a day or so, it will give ample warning of the approach of ovulation and the need for absolute avoidance of intercourse and genital contact if a pregnancy is not desired at this time.  Sperm are kept alive and healthy by this mucus which is vital to fertility.

You may also notice that this slippery sensation is accompanied by a feeling of fullness, softness or swelling of the tissues of the vulva.  Many women described it as a feeling of “ripening” – something they can associate clearly with fertility.    No other signs of fertility, such as pain or spots of blood, are as precise or reliable as the mucus.