Help! 13dpo

I’m so confused! I’m currently on 13dpo. I ovulated on cd17 confirmed by opk and bbt. I typically start AF on 12dpo , almost always upon waking. I was hopeful when AF didn’t come yesterday but disappointed by a temp dip this morning. I had a tiny bit of light pinkish Brown CM this afternoon and very minor cramping on my left side. I’ve never experienced this before, it’s usually very obvious when my period begins by bright red blood. I decided to take a wondfo and can’t tell if I see a faint line. Is it possible to have implantation bleeding at 13dpo? Thanks!