Menstruation delays what reason is there a few haemorrhage

Menstruation delay has a small amount of bleeding, may be to menstruation, a handful of women menstruation ahead or delayed within seven days are normal, menstrual delay phenomenon, may be often stay up late, emotional excitement, mental stress, lack of rest caused by endocrine disorders. In addition, menstrual delay accompanied by a small amount of vaginal bleeding may also be caused by qi and blood deficiency.