Normally, pregnancy can be determined by taking a blood test for HCG level 10 days after sexual intercourse. HCG refers to chorionic gonadotropin. HCG increases rapidly after the embryo has implanted in the endometrium. For patients with irregular menstruation, the morning urine test can be done several times regularly after 10 days of sexual intercourse, and if the morning urine test shows pregnancy, you can go to the hospital laboratory to check whether you are pregnant. If the blood test HCG >5mIU/ml indicates pregnancy, the doctor will often assess the pregnancy outcome based on the specific results of HCG. If the HCG doubling is not high or there is a decrease, it indicates a higher likelihood of an adverse pregnancy, such as miscarriage, embryonic abortion, ectopic pregnancy, etc. If the blood HCG test after 10 days of sexual intercourse shows no pregnancy, it is necessary to monitor regularly until the onset of menstruation to be sure that there is no pregnancy. If pregnancy is detected, it is important to monitor the HCG dynamics several times to determine the development of the placenta and fetus.