Okay I am a 18 year old mother of 2 and my peroids have been very regular but for the past 2 months ihave had it for 3 and a half weeks very heavy with clots I will have it for 3 and a half weeks then it is gone for 2 or 3 days then back for a nother 3 and a half weeks this has been happening for 2 months know I had an ultrasound to see if I had cysits on ym overies and I don't what advise or anythign do you have??

You NEED to visit your OB/GYN. This could be causing you to be low on iron, and there could be some serious issues causing this. Only your doctor can diagnose and treat you properly.