17 days late....😯😯😯

Diabolique
Hey my name is dede, I am 20 years old and my period is 16 days late the only symptoms I am having is cramping and sometimes nausea don't mean throwing up..... My last period was on July 20th 2016 and today as we speak is sep 7 2016.... my period was supposed to come August 11th... well on that day i was only spotting it was very light and pink... And only when i wiped and even than it wasnt like it wasnt spotting for the whole day it was like a couple of hours than stop ... than a day want by and noting happen and than i was spotting again the next two days and than It stoped completely the same way. I took a test a couple days ago and it was negative.... so I don't know what's going on any suggestions anybody...