Spotting

So today I am officially 4 days late. I started spotting this morning. Dark brown blood and when I use the bathroom it looks like flakes in the toilet and when I wipe. This is definitely new for me. I started cramping a week after ovulation and and having period cramps since the day that my period was supposed to show. Anyone ever have this experience or something like this before? My period is never late. I also got a bfn Monday morning.