HELP!!!! Don't know what to think???

Okay so today is 13 dpo....and AF is due tomorrow.....and I have been feeling pulling and tightening I'm my abdomen for past few days, sore breasts, and feeling blah and this morning I have a very light pink discharge and a BFN to boot....so IDK if it's possible to have implantation bleeding this late or not anyone???? 😢