what's wrong with me!!??

Lece
I posted the other day..I had some light spotting August 30-September 1.   It was never enough to fill a liner and was pink in color sometimes a darker pink.
 So here I am. 8 days past my missed period. 4 negative pregnancy tests. I will have short (5min) bursts of low setting cramps, sometimes back cramps... I figure if I don't have a period by next week I'll call a doctor.. But for now I feel like I'm at a loss! Has anyone experienced this? Can stress make you this late?