There are several reasons why a woman have delayed menstruation and this could be due to unhealthy diet, stress (emotional or physical), sudden weight gain or loss, caffeine, alcohol, and
smoking. Gynecological conditions like polycystic ovarian
syndrome (PCOS), and
uterine cysts or polyps, can also bring about alteration in menstrual cycle. Gall stone will not cause delayed periods. However, pregnancy is still the most common cause of delayed or missed period.