No AF and BFN

Kimberly • Perfectly Imperfect
So AF was suppose to come on Friday the 20th. There's still no sign of her and I'm nearly a week late. I took a hpt two days ago and it came up negative. Also, I had some brown and light pink spotting on the 9th and 10th. Haven't been stressed and periods are normally on time. Anyone know what could be going on?