This hormone starts being produced in the placenta which is firmed during implantation of the embryo in the uterus. The process of implantation is over by the second week of conception and hcg production starts. This hormone circulates in the maternal blood and is excreted in urine as well.

The urine pregnancy card kit test is based on identification of the presence of this hormone in urine. On the first day of the missed period it's concentration in urine is very less. That is the reason some people get a faint line which becomes confusing. Hence this test should be taken only a day after the date of the missed period. First urine of the morning is most preferable for an accurate result. In case of confusion one must wait for 3 to 4 days more and then repeat the test again. If it is positive then a darker pink line will definitely manifest to confirm the good news. Sensitivity of various brands of the kit available in the market also differs. The brands mention the percentage of error or the accuracy of the kit in the small chit of paper in the packaged box or on the box itself which is based on the clinical trials done by the company.

Other than this card test, blood test for beya hcg can also be done to confirm the pregnancy.

Yet a transvaginal scan remains the diagnostic and confirmatory investigation for any pregnancy.