Thanks for the query.
According to your description the possibilities are:
imbalance leading to heavy and irregular flow.
-Structural causes like fibroids, polyps.
hormonal imbalance etc.
So you once consult gynecologist, go for physical examination and ultrasound
by this the possible cause for your problem can be made out and treatment can be taken accordingly.
For more details you can ask me through: http://www.healthcaremagic.com/doctors/dr-sree-gouri-sr/63429