You may be wondering which irregularities in your mucus pattern and your menstrual cycles should be considered abnormal. There are different kinds of ovarian activity that are completely normal responses to different times and events in your life. Your Billings Ovulation Method® chart will help you make the connection between what is going on with your mucus pattern and menstrual cycle and what is going on in your life and your body. So let's take a look at these normal "irregularities" before we look at what might be abnormal.
The lining of the uterus, called the endometrium, thickens during each menstrual cycle in response to the hormone oestrogen. Progesterone levels begin to rise around the time of ovulation, changing the endometrium to make it ready for the implantation of a fertilised egg. If conception doesn't take place, the levels of progesterone and oestrogen fall, causing the endometrial lining to be shed.