Menstrual calendar 2015 - 2018.
Ladies: enjoy this menstrual calendar for 2015-2018.
How to use it: Mark the first full day of menstruation each cycle, and connect the marks with a line. Reading left to right, a horizontal line indicates a 28-day cycle. A line sloping up indicates a shorter cycle, a line sloping down indicates a longer cycle. If there is no line that is straight, the cycle is variable.