5 dats late

My AF is 5 days late. Its never late. I have mild to no cramping, the sorest boobs ever, nausea, weird dreams, trouble sleeping, & last night I woke up in a pool of sweat even tho i had the AC on (it was easily 50 degrees in my room). Took a test & it was BFN. Should a wait a few days to take another one? I was thinking maybe its too early to detect on a test just yet (if im following my tracker correctly, i would be about 4 wks along right now). This is so frustrating. Why would it be negative???