Implantation Bleeding or Period

I thought I was starting my period when I saw some blood but my normal periods come fast and heavy like fill a tampon in an hour or 2 same with my cup. I have to wear pads with both cause they fill so fast. But I’m on day 2 and haven’t even had to use a tampon or cup and I haven’t filled a pad yes I’ve been replacing them but not because it’s full or even close it’s just a line of blood very thin and some pads don’t even get that. So I’m super confused. Any advice or anything would be helpful.