Started my period early, too heavy to be implantation ? Details below

My cycles have been an average of about 34-36 days and I have PCOS but this month my period came on the 29th day which isn't normal. I was cramping really bad and bled for a whole 6 days, but now I'm just spotting so altogether it's been 8 days which isn't normal. I'm not having any weird smells or discharge, so I don't think it could be anything like am STI or something of the sort. Some women say implantation bleeding, but I doubt it cause I was cramping and bleeding so heavily... then my friend said she had the same issue then found out she was pregnant.... then google said something about someone's doctor telling her that when the pregnancy hormone isn't high enough yet you can have a "period" still but you're actually pregnant.

Haven't peed on a stick cause I don't wanna waste it.

Just looking for opinions or stories. Maybe my hormones shifted? What do you guys think?