It could be one of several causes. For one thing, stress can cause longer than usual bleeding. One time in college, I bled for 12 days. After I saw the dr and he told me there was nothing wrong and that it was just stress, the bleeding stopped two days later. So I figured that was the proof he was right. Another thing I know that can cause irregular bleeding like that is thyroid issues. (specifically hypothyroid) So if you're having any other symptoms (fatigue, constipation, feeling cold, thinning hair, etc.), make sure and tell your doctor and ask him/her to check your thyroid. If you have access to a good integrative medicine specialist, they can check all of your hormones to see if there is an imbalance that could be causing your problem. There may be other possible causes, but those are a few that came to mind. I hope that the bleeding stops very soon! Good luck! Please keep us posted!
its a weakness to have long periods than usually you have . you can be anemic too, i think you shud see the doctor and also start some iron supplements too. Good luck