1. The time of detection. HCG usually appears in urine a few days after implantation of the fertilized egg, and a certain amount must be reached before it can be detected. Therefore, for women with normal menstrual cycles, it is necessary to delay menstruation before HCG can be detected in the urine. Women with long menstrual cycles or abnormal ovulation may only be detected after 40-44 days of amenorrhea.

2. Some diseases and drugs may cause false positive results. Some tumor cells, such as hydatidiform mole, choriocarcinoma, bronchial cancer, and renal cancer, can also secrete HCG.

3. Do not use expired test strips. Because chemical reagents lose their effectiveness over time, it is important to pay attention to the production date when purchasing.

4. Do not use damp test strips.

If the self-test result is negative and your menstrual cycle is still approaching after one week, you should do another self-test. If it's not positive, it's best to see a doctor. Believe in your own body. If you experience various symptoms of pregnancy, regardless of the self-test results, you should consider that the principle of early pregnancy test strips is only preliminary testing, and there may be errors when using them. The best method is to go to the hospital for HCG blood test, HCG urine test, and B-ultrasound examination. If you are not ready to welcome your baby, it is necessary to detect early signs of pregnancy and determine whether you are pregnant as early as possible, in order to undergo abortion surgery in the later stage.

5. When women of childbearing age experience early pregnancy reactions such as amenorrhea, they cannot determine whether they are pregnant based solely on one early pregnancy test strip. The most reliable method is to conduct a comprehensive examination, especially for weakly positive cases, HCG blood test, HCG urine test, and ultrasound examination. In order to take measures as soon as possible.

6. After three months of pregnancy, HCG levels will decrease. If early pregnancy test strips are used at this time, negative or weakly positive results may appear.

7. If the usage period is exceeded, the effect will be lost. Please go to the hospital for examination in a timely manner! [1]

Colloidal gold early pregnancy test strip urine test positive

Positive urine test prompt β— HCG ≥ 25U/L, the strength of the T-line reflects the concentration of HCG.

1. Pregnancy:

(1) Normal pregnancy: During normal pregnancy, HCG reaches its peak (approximately 50000-10000U/L) 60-70 days after menopause,

Inspection method

Starting from 1-2 weeks of continuous decline, it returns to normal 2 weeks after delivery. The early T-line deepens with increasing HCG, and a "high concentration effect" appears near the peak (the T-line weakens with increasing HCG).

(2) Ectopic pregnancy: After 8-9 days of ectopic pregnancy β— HCG only returned to normal. Urine tests can also show positivity.

2. Recovery period from miscarriage or childbirth: general β— It takes 30 and 19 days for HCG to return to normal after induced abortion and natural abortion, respectively, and 12 days for full-term delivery without residual placenta to return to normal. A positive urine test may appear before returning to normal.

3. Reproductive system diseases: molar pregnancy, invasive molar pregnancy, choriocarcinoma, trophoblastic tumors and other reproductive system diseases β— HCG levels were abnormally elevated (>100000U/L). The high concentration effect caused by high concentration actually weakens the T-line.

4. Cross reactivity caused by homologous A-chains: In a few women of reproductive age, the LH peak during ovulation may be falsely positive due to homologous A-chains, especially when hormone levels are high and urine is concentrated.

Colloidal gold early pregnancy test strip urine test negative

1. Negative urine test prompt β— HCG<25u>

(1) Non pregnancy.

(2) Ectopic pregnancy: Patients with ectopic pregnancy may experience urinary incontinence β— HCG is below 25U/L. Therefore, in clinical practice, it is necessary to combine blood β— Assisted diagnosis includes HCG, clinical symptoms, and imaging examinations.

2. High concentration hook effect: β— When the HCG concentration is too high, false negatives may occur due to the "high concentration hook effect".

3. Improper use of reagents: When the urine sample exceeds the MAX line or the sample addition speed is too fast, due to the chromatographic force, the sample does not bind to the labeled colloidal gold antibody and swims directly to the C and T line areas. At this time, regardless of the β— There are no C or T lines for the HCG content.

4. Reagent failure: At this time, regardless of the β— There are no C or T lines for the HCG content.