How to you track the days of your menstrual cycle?

First spotting day 1: Counting the menstrual cycle starts with Day 1 being the first day a woman notices the slightest sign of her cycle to start, for example spotting that then becomes a full menstrual flow. Ideal cycle length is 28 days from the first day to the day before the next menses. In a 28 days cycle a woman ovulates on 28-14= Day 14. Over a 24 hour time window she is able to conceive.