🟥 Red date is the first (1st) day of your last period

🟩 Green days are the fertile days, including ovulation, when the likelihood of remaining pregnant is higher

🟧 Orange day is the estimated first (1st) day of your next period, based on your estimated numbers of days between periods (the standard number of days of a menstrual cycle is 28. However, it can differ from woman to women, being smaller or greater, so it is highly recommended to count the days between the first days of your periods, throughout multiple months, to obtain a more accurate number)