Why hasn't my period come and I'm not pregnant?

In addition to pregnancy, the following are some common factors that can cause delayed or missed menstruation: 1. Stress and emotional changes: Mental stress, anxiety, or emotional fluctuations may affect hypothalamic function and disrupt hormone secretion, leading to menstrual cycle irregularities. 2. Weight changes: Being underweight or overweight can prevent the body from producing and releasing eggs normally, thereby affecting menstruation. 3. Excessive exercise: High-intensity or prolonged physical activity may lead to excessive energy consumption in the body, affecting hormonal balance and causing menstrual disorders. 4. Hormonal imbalances: Conditions such as polycystic ovary syndrome (PCOS), thyroid dysfunction, or other endocrine disorders may affect menstruation. 5. Medication effects: Certain contraceptives, hormone therapies, or specific psychiatric medications may alter the menstrual cycle. If menstruation is significantly delayed and pregnancy has been ruled out, it is recommended to consult a doctor for a detailed examination.