Sore boobs, lower back pain, brown discharge, a week late period but a negative pregnancy test?

Pregnancy possible: The possibility exists. If you are one week late and still haven't had your menses, you should perform a home pregnancy test. If it is negative, repeat in one week.

Repeat HPT in wk.: Reasons for missed /late periods: low body weight, obesity, marked weight gain or loss, over-exercise such as in endurance athletes, breast-feeding, stress, illness, eating disorders (bulimia or anorexia), travel, hormone irregularities, drug use, medications (i.e., birth control) or med problem (polycystic ovary syndrome or Asherman’s syndrome. #1 reason for missed period is pregnancy.