No pic but is this implantation or AF

Susie
So I'm suppose to start my period tomorrow. But I thought I started today usually when I start I see it in my underwear first. This was at 5:30 pm it got a little darker but not red more brownish and still only when I wiped not in my underwear. Now it's just spots back to the light pink color. I have never had a period like this. So I'm just a little confused