When you take a home pregnancy test, you look at the results window to see whether there are two lines or just one. The first ... positive test result and evaporation line is to check your test ...

Pregnancy tests with blue or pink dye typically show one line if the result ... Important: If a test gets wet or is left out too long, an evaporation line, which is a faint streak may appear ...

If that control line doesn't show up, the test didn't work and you should take another one ... "A faint pregnancy test line is a true reaction to the hCG in your urine, while an evaporation ...