3 days late, spotting 12 & 13 DPO, BFN

I usually have an extremely regular 26 day cycle. I've never had a late period in my life.. I'm 3 days late and so far keep seeing BFN's. At the first sight of spotting, I figured I was out this month bc I just knew AF was coming (because I felt crampy as well). No spotting/cramping today. I'm wondering if I implanted late and it's actually sticking or if I'm experiencing my first EVER late period (under stress from trying to buy a home, but I'm in nursing school so I am ALWAYS under stress lol). Anyone here ever get a BFP this late in the game?