Medical Abortion Pill, I might need to get a D&C

Hi, I have a question. I took an abortion pill back in December of 2011 (last year) I was about 6 weeks pregnant so I was early. I took the abortion pill and everything went smooth. I felt the side effects very quick, bleeding and cramping. I was told that I was going to be bleeding for a bit. I felt like the abortion worked since I was bleeding and I just knew that my body wasn't feeling "pregnant". Ever since then I have been bleeding, NON STOP. There were times where I was bleeding and not bleeding for a couple of days. NOW, I'm not bleeding. I went to go to the doctors and told her about the situation, she mention that it was possible that I might need to get a D&C that maybe there's stuff left inside that hasn't been removed with the pill that is making me "still pregnant". I'm going to the doctors next week (obgyn). I took a urine test at my doctors & blood work too and she said that I was about 4 weeks pregnant. I haven't had sex since my abortion pill, so it's impossible that I got pregnant. So I'm thinking there is stuff still left inside of me. I need someone's help and advice