#1 Due to taking birth control pills
#2 Because of acute weight loss
#3 Due to hormonal imbalances
#4 Excess of exercise
#5 Improper diet
#6 Due to lot of stress
#7 Thyroid disorders
#8 Certain food allergies
Share the article with as many females as possible so that they can know the reason behind their irregular menstrual cycle and can cure it as soon as possible.
Source: http://www.wittyfeed.com/story/12540/8-reasons-behind-your-irregular-periods-you-might-not-be-aware-of