For women with regular menstrual cycles, a pregnancy test can be used for more than 7 days after the menstrual period. The principle of the pregnancy test is to monitor the value of human chorionic gonadotropin produced by the placenta, which is found in the urine in the early stages of pregnancy. If it shows two bars, it is positive and means that you are pregnant. If it shows 1 bar, it is negative, which means that you are not pregnant. Premature test results may be inaccurate. Testing within 1-2 weeks after the postponement of menstruation or doing HCG test can improve the accuracy rate. Since the body’s hormones are unstable in the early stages of pregnancy, performing multiple tests can improve the accuracy value and also avoid false pregnancy symptoms caused by diseases or medications.