Home pregnancy test. Packet and contents of a 'Clear Blue' home pregnancy test kit. The test checks for the hormone human chorionic gonadotropin (hCG) that is present in the urine of a pregnant woman. A dipper with an absorbent end (bottom) is placed in the urine stream, or dipped in a urine sample. Blue lines display the results after one minute. A round window (not seen) gives a reference line that shows that the test has worked. A line in a square window (not seen) confirms the presence or absence of hCG. HCG is produced by the placenta, the organ that attaches an embryo to the wall of the uterus.