Other reasons for delayed period?

Many : Pregnancy, anovulation, peri-menopause, hormone manipulation (ocps, depo-provera, etc), premature ovarian failure (pof), stress, poly cystic ovaries (pco, stein-leventhal syndrome), prolonged follicular phase, or just a normal variant. It's normal to occasionally miss a period or have a delayed one. I hope that helps.

Some reasons:: 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.