Why an HCG test pick up my pregnancy?

An HCG (human chorionic gonadotropin) test detects the presence of the HCG hormone in a person's urine or blood. HCG is produced by the developing placenta during pregnancy, and its levels rise rapidly in the early stages of gestation. The placenta produces this hormone because it supports early pregnancy and maintains the corpus luteum. HCG is considered a reliable indicator of pregnancy and is the basis for most home pregnancy tests and laboratory pregnancy tests.

Here's how an HCG test detects pregnancy:

1. Implantation: When a fertilized egg implants into the uterine lining, it begins to develop into an embryo. The developing embryo releases HCG into the bloodstream.

2. Detection: After implantation, HCG levels start to rise rapidly, doubling every 2-3 days in the early stages of pregnancy. As the pregnancy progresses, HCG levels continue to increase but at a slower rate. They usually peak around 8-12 weeks of gestation, and can last up to 16 weeks.

3. Urine and Blood Tests: Both urine and blood tests can detect the presence of HCG. However, blood tests are more sensitive and can detect lower levels of HCG earlier in pregnancy, sometimes as early as 6-10 days after ovulation. Urine tests are typically used as home pregnancy tests and measure higher levels of HCG due to their lower sensitivity.

The presence of HCG in a person's urine or blood suggests a possible pregnancy. A positive result on an HCG test is usually followed by other tests and clinical evaluations to confirm pregnancy and monitor its progress.