"ive had my period now for 2 weeks with lots of blood clots. What is causing this?"

There is no way to tell you an accurate answer over the Internet, but I do recommend talking to your doctor. Two weeks with several clots is a bit on the heavy side. You should be monitored for anemia with so much blood loss.

You are Haemorrhaging you need to go to the Hospital for a Blood Transfusion. That happened to me. I was Haemorrhaging 2 years ago. A lot to do with your IRON LEVEL. It appears to be VERY VERY LOW and you need to take some Iron Tablets. But go in the Hospital and tell them why, or consult your doctor ASAP.