If you have chest pains and your period is delayed for 10 days, and you have had sex after your period without contraception, you should exclude unwanted pregnancy and use a test strip or blood test for HCG to confirm whether you are pregnant. If you are pregnant and want to have children, you can take folic acid tablets to prevent fetal neural tube abnormality and have regular maternity checkups in the future. However, if there is no need to have a baby and the ultrasound shows an intrauterine pregnancy with a small gestational sac, you can choose to terminate the pregnancy by medical abortion or abortion. If you completely exclude unwanted pregnancy, it may also be caused by endocrine disorder or abnormal ovulation or even non-ovulation resulting in delayed menstruation, usually in combination with ultrasound examination. If the thickness of the endometrium is moderate, you can consider taking progesterone capsules or progesterone injection to promote the onset of menstruation.