Implantation bleeding??? or early period??

I would be 9 dpo and I am so confused. I started bleeding a very little bit but I usually would have really bad cramps. I get them before my period which I havent and when I first start I have very painful cramping. I have now nothing. At first it was very bright pink but just the tiniest bit. I used a tampon and it just had a little pink and brown. I may have started my period early but 4 days early? That's never happened. Anyone actually have had implantion bleeding? What was your experience? Thank you.