The menstrual cycle is not the same for every woman. On average, menstrual flow occurs every 28 days (with most women having cycles between 24 and 34 days), and lasts about 4-7 days.
However, there is a wide variation in timing and duration that is still considered normal, especially if your periods began within the last few years.
A small percentage of women have periods more often than every 21 days or less often than every 35 days. These variations may be normal.
Menorrhagia
Metrorrhagia
Amenorrhea
Dysmenorrhea
Logorrhoea
Vaginal bleeding
Anorgasmia
Abnormal uterine bleeding