Irregular periods with clots and pain can be seen in certain uterine abnormality like fibroids in uterus,adenomyosis, endometriosis or hormonal imbalance like thyroid hormone imbalance or oestrogen-progestrone imbalance might also be a cause....this things need investigations like transvaginal ultrasound to rule out the uterine abnormality. Hormone profile to rule out any imbalance and most of the times the condition is treatable. So kindly consult a gynecologist for further management to rule out these things.

If you  really want to know  the root cause of your problem and heal, please  read my blogs on www.truhealing.com or practo health  feeds. Hope that helps....