My last period was August 26 2018 it lasted 4 days which is normal. My periods are always 4/5 days and around 30 days apart. I did not have a period for the month of September and still no sign of a period as of today 10/1/18! Took a test today it was negative. I’m just not understand what’s going on. No abnormal symptoms my periods are not abnormal but I’m having just the normal tender breast before expected period.