When the pregnancy test is used, there are two contrast lines. One is the C-zone, which is a control line, and the T-zone is the test line. The presence of a very thin line in the T zone during the pregnancy test indicates that the pregnancy is also present. It is only because the days of pregnancy are relatively short, it may not be obvious when the test is performed, so monitor again at an interval of 1-2 days if possible, as long as it is getting darker, it means that the fetus is developing well. You can also go to the hospital for a blood test to determine if the HCG level is within the normal range, and depending on the situation, preventive fertility treatment can be administered. After the test, you can go to the obstetrics and gynecology department for an ultrasound to determine whether the pregnancy is intrauterine or ectopic, as not all pregnancies are intrauterine.