If your menstrual cycle is usually regular, with a cycle of about 28-30 days, a delay of 6 days in your period is likely to be pregnancy. More than 12 days after intercourse, using a pregnancy test stick or test paper is relatively accurate, the accuracy rate is about 90%. If pregnancy is completely ruled out, it is also possible that endocrine disorders or ovulation abnormalities lead to delayed menstruation, if recently often stay up late, sleep late, regular work and rest, dietary irregularities, change of environment, mental stress or oral medication affects the menstrual cycle, may lead to delayed menstruation. In this case, it is recommended to come to the hospital for an ultrasound examination to see the condition of the uterine adnexa, blood tests for HC nodes and endocrine six, and oral progesterone capsules or intramuscular progesterone injection under the guidance of the doctor to promote the onset of menstruation, if necessary.