It could not be simpler - just add a little saliva to the top of the unit and observe through the included microscope the structure of the saliva. This form of testing can sometimes be difficult to interpret and can give a positive result over a longer period than ovulation tests but used together with ovulation tests, temperature and other body changes noted on the Fertilityplan chart (see what we mean below) will ensure you don't miss that critical and very short time when the egg is released from the ovary.
How exactly do you measure a menstrual cycle?
Very simply a menstrual cycle defined as starting on the day of first bleed to the start of your next bleed. So CD12 would be Cycle Day 12 of your cycle and would be 12 days after you first started your period.
What other bodily changes should I look for to know when I am about to ovulate?
The consistency of cervical mucus changes throughout the menstrual cycle. Usually after you finish your bleed you will have 3/4 days when you have dry days. The wetness then increases daily usually lasting about 9 days at which point the mucus will become plentiful, slippery, clear and stretchy. The best comparison is that it is like egg whites and at this point it is a good sign that ovulation will occur in the next couple of days. After ovulation occurs the mucus will again become more sticky less stretchy and then dryer again.