It is normal for menstruation to be delayed by up to 7 days from the last normal menstrual cycle. It may be related to physiological factors such as drinking cold water, eating cold food, bad habits, excessive stress, staying up late, etc. It may also be related to medication and pathology. It can also be related to medication and pathological factors such as infection and non-infection.
If a woman of normal childbearing age, who is sexually active and usually has regular periods, experiences symptoms such as delayed periods and abnormal menstrual flow after intercourse, pregnancy causes should be considered as a priority.