The absence of menstruation doesn't necessarily mean pregnancy. The reasons for late periods and irregular cycles can be divide into 3 groups:
- Physiological: stress, sudden weight changes, climate or time zone changes, breastfeeding (lactational amenorrhea), etc.
- Medically induced: The cycle disruption is associated with taking or canceling medications, including hormonal contraceptives and antidepressants.
- Pathological: The cycle disruption is caused by diseases such as ovarian pathology, uterine diseases, endocrine system disorders, etc.
If menstruation doesn't come 7-10 days after the expected date, you should consult your doctor.