A pregnancy test is a tool used by girls to test whether they are pregnant or not. In daily life, a pregnancy test can be a convenient, quick and accurate and cheap way to test for pregnancy. So how can you tell if you are pregnant? You need to look carefully at the result display on the pregnancy test to determine. What is the principle of pregnancy test? HCG is usually secreted in large quantities after fertilization and continues to increase in the blood and urine. The pregnancy test is used to determine whether a girl is pregnant by detecting the level of HCG in her urine after pregnancy. When to use a pregnancy test and get the most accurate result? Many girls don’t know when to test a pregnancy test and whether to test after sex or after menstruation. The most accurate time to use the pregnancy test is 7-10 days after menstruation, and the results are more accurate when the test is performed in the early morning with morning urine drops on the reaction zone of the pregnancy test. How can I tell if I am pregnant by using a pregnancy test? There are two letters C and T in the observation area of the pregnancy test stick, which indicate the quality control area and the test area respectively. After the morning urine is dropped into the reaction area, red lines will appear in the C and T areas, and four kinds of results may be detected through different combinations of red lines, namely positive, negative, weakly positive and invalid, which correspond to four kinds of situations, namely pregnant, not pregnant, suspected pregnant and pregnancy test failure. 1.Two red lines indicate pregnancy: If a clear red line appears in both the C zone and T zone, the result is positive, indicating pregnancy; 2.One red line indicates no pregnancy: If only one red line appears in the C zone and no red line appears in the T zone after waiting, the result is negative, indicating no pregnancy; 3.One deep and one shallow suspected pregnancy: If a clear and obvious red line appears in the C zone and a shallow red line in the T zone, the result is weakly positive, indicating suspected pregnancy. Weak positive, at this time indicates suspected pregnancy, may be a short period of pregnancy caused by the low level of HCG, T zone is not enough to appear clear red line; 4, no red line indicates that the test is invalid: if the C zone does not appear red line, it indicates incorrect operation or reagent strips have deteriorated and damaged. In addition, it should be noted that the pregnancy test can only detect whether the pregnancy, after pregnancy need to be alert to the case of ectopic pregnancy, the best way to deal with it is to go to the hospital for blood HCG testing as well as ultrasound. Warm tips: 1. If pregnancy is detected, you can go to the hospital for further examination after 6 weeks of menopause, such as ultrasound examination, etc.; 2. If you have abdominal pain, vaginal bleeding and other uncomfortable symptoms after pregnancy is detected, it is recommended to seek medical attention immediately to prevent miscarriage and ectopic pregnancy.