My last AF was 8/23. I'm a week late and 2 tests, 2 BFN's.

My last AF arrived 8/23 n lasted til 8/26. I had a 40 day cycle last month. Now I'm 8 days late n both hpt's have been neg. 9/9-9/12ish I spotted light pink/brownish/mucus-ee stuff n it just disappeared... Anyone have any clue what could be going on? PLEASE HELP! I have VERY sore boobs n nausea that comes n goes n a few days I've woken up STARVING! PLEASE ANY ADVICE??