It is more accurate for a woman to test negative with a morning pregnancy test or pregnancy test 20 days after the last intercourse, but in very few women, the fertilized egg does not settle in the uterine cavity after intercourse, but in the fallopian tube or abdominal cavity, and the HCG hormone produced is lower and slower, so the HCG in the urine 20 days after intercourse may not have risen significantly, so a false negative may also occur. Therefore, if a woman tests negative 20 days after intercourse, she can temporarily observe for a week. If she does not have a period, she can retest with an early pregnancy test or a pregnancy test. If it is still negative, you can be sure that you are not pregnant but simply have a delayed menstrual cycle. If the test is weakly positive or positive after a week, you should go to the hospital for a blood HCG test and an ultrasound to determine if the pregnancy is intrauterine or ectopic. Because women with ectopic pregnancy cannot continue the pregnancy, they are prone to rupture of the mass and cause hemorrhage.