The test line is visible every time you test. Sometimes it even turns blue with in the time frame. I took a test the other day and it was blue but faint. Other people even confirmed the line and believed it was a positive. Well I am not pregnant. But these tests get you to come back and buy more! Luckily I have been pregnant before and have read just about everything there is to read about evap lines and pregnancy tests. So I knew not to get my hopes up. I feel bad for the couples that have been trying for years... take one of these tests, then get the evap line that pops up in the time frame with a hint of blue.... then they celebrate just to have their doctor tell them they are not pregnant.