12 dpo, light brown spotting and zero signs of AF

I've never ever had spotting before! It started on the 7th, I thought I was getting my period early. Yesterday and today after wiping I barely see a little brown. I haven't had any cramps, and my boobs arent sore at all which is usually a tell tale sign of my period (I ALWAYS get sore boobs a few days before I start). No usual signs of AF and I am SUPPOSED to start today... I took a pregnancy test yesterday but it was a BFN :( Was it maybe just a light period or possibly implantation bleeding? It's officially been one year since stopping BC and TTC