Question about implantation bleeding/TTC

Hi all! AF was due Friday, but I think she came today. I took a pregnancy test this morning before I got AF and it was negative. Is there any chance I'm having implantation bleeding or did my period just come early? It hasn't come early since I've been off BC, only on time or a little late, but the pregnancy test was negative so I am thinking I'm out this month. Thoughts?