It's a normal physiological event. Many don't realise the significance of the changes in the mucus until it's explained to them. Mucus, which is secreted from the cervix, changes in appearance and texture at different times during the cycle. These changes vary from woman to woman. Each woman can be taught to recognise her particular change to a more 'fertile-type' mucus before ovulation.
Mucus assists the sperm to travel and also influences their life span.
Sperm survival is very dependent on the cervical mucus which is known to increase their life to up to 5 days. After ovulation has occurred, a definite change from this 'fertile-type' mucus can be observed. There's a simple way of recognising these mucus changes and recording them by using a chart and coloured stamps. A woman's basal body temperature varies during the cycle. Special charts make the temperature pattern easy to record.