Menstruation
Menstruation is the most visible phase of the menstrual cycle and its beginning is used as the marker between cycles. The first day of menstrual bleeding is the date used for the last menstrual period (LMP). The typical length of time between the first day of one period and the first day of the next is 21 to 45 days in young women, and 21 to 31 days in adults (an average of 28 days).
Anovulation
The standard dosage for first-time takers is 50 or 100 mg of clomifene per day for five consecutive days, starting early in the menstrual cycle, usually on the third to fifth day counting from the beginning of the menstrual period. In case of amenorrhea, a period can be induced by intake of an oral progestin for 10 days. In absence of success, the dosage can be increased in subsequent cycles with increments of 50 mg. However, at a dosage of 200 mg, further increments are unlikely to increase pregnancy chances.