The First Step Pregnancy Test is a fast and direct individual test for chorionic gonadotropin (hCG).in the urine. HCG is a hormone produced by your body during pregnancy. HCG is in your body even when you are not pregnant, but when conception occurs and the fetus begins to grow, levels of this hormone (measured in IU units) increase in the blood and urine. If it has reached 25 IU, the test is positive, which means that you are probably pregnant. Some medicines, such as fertility drugs, can have a false positive effect. The same is true of some diseases. For these reasons, in case the test shows a positive result, contact your gynecologist as soon as possible.