a menstruation cycle usually has 4 phrases. around 28 days, or a month. menstruation, repair phrase, receptive phrase, and premenstrual phrase. between repair phrase and receptive phrase, an ovum is release from an ovary. that usually occurs during the 13th to 15th day of the cycle. therefore, AROUND the first 12 days should not be any eggs. note that each women has different cycle lengths and each cycle may be different.