Question for you ladies. What does implantation bleeding look like and when does it usually happen?

My period isn’t supposed to start until Sunday and I am quite regular, my period never comes early. A couple times it’s even come a day later than what Glow predicts. I am 13 dpo and my period is supposed to start Sunday, but I am having some spotting. Not nearly what I would have if I in fact was starting my period. I do have mild cramps, which is different than usual as well.

I am just trying to hold onto some hope that this may still be my month....