Implantation bleeding or period?!

So today is my second day on my period and it's very very light. Usually i can only use maxi pads on the 2nd day but it's been panty liners all day. I have had unprotected sex and my period came 5 days early? I had read that implantation comes around the same time you would expect to get your period. Note: the color varies from pink to brown. Any help is very appreciated!