Late period. Bfn. Spotting?

Brittany • 26, married, one girl and two boys.

Hey guys, I'm 13 dpo. I have a short luteal phase and af was due 2 days ago. She never came. I've been testing and bfn. Today I had some light brown bleeding once when I used the restroom. Nothing since.

I never spot before my period starts. Lol I go from zero to HEAVY in the blink of an eye when I get AF.

Any ideas?