Implantation bleeding? Help

So for the past 3 days I was only spotting a little bit of brown and light pink blood. My period was supposed to come on Wednesday and nothing. Yesterday I was spotting lightly here and there. Last night it was a little more heavier, enough to fill a regular tampon, but today I'm dry for the most part with some cramping. A regular period for me lasts 5-6 days with a pretty heavy flow for the first 2 days. Heavy enough to fill super tampons. Do I count this as a period? Could it be implantation bleeding? I know implantation bleeding is supposed to be light spotting, could it possibly fill a regular tampon? Any opinions would be greatly appreciated!