###Human: Birth control pills taken for regularizing period causing sporadic periods. Why? ###Assistant: Hello, Welcome to iclinq.com. I can understand your concern and what you are going through is a hormonal problem. The regularity gradually sets in with maturation of the HPO (hypothalamic-pituitary-ovarian) axis ( as you grow older), and the treatment of choice is hormonal pills. The possibilities of your problem despite pills maybe 1) Missing pills in between. 2) Taking pills not on time (these two are the most common causes for such a scenario). 3) Dose of the pill may not be enough. However, as you are complaining of severe pain, have an in-person gynecologist opinion. USG (ultrasound) abdomen is done to rule out uterine, and ovarian pathology. Nothing big to worry about and continue with hematinics. I hope this helps. Hormonal. USG abdomen and pelvis, Hb. Uterine/ Ovarian causes. Hormonal. OCP (oral contraceptive pills) after the scan. Excess weight gain can alter your cycle, so concentrate on weight reduction and iron-rich diet.