Hey babe, from my experiences and understanding implantation bleeding is brown like old blood and there usually isn't a heavy flow. I you have a heavy flow of red or dark blood then maybe you have gotten your AF early or you may have had a chemical pregnancy - if the disharge has a lot of tissue and clots then that is what happens when you have a chemical pregnancy but it may just be an abnormal period. If I were you I would go to the doctor just to get it checked out. I have heard from some women that they get what looks like thier period for the first few months of thier pregnancy. Good luck babe!! Xx