Question: Period is 8 days late. BFN this morning

I use an app to track my ovulation and cycle. I was ment Mojave my period 21/08/2018 but didn't arrive, took a HPT with FRER negative, and continued to do this every 2 days. This morning another HPT negative. My breats have been really sore since the day I missed my period, but other than that I feel okay. A week before expected period I had brown sporting was like stringy, and after that I have been spotting brown blood nearly everyday since it's only noticeable when I wipe after using toilet. What's going on could somebody help me?