If you're hoping for a positive pregnancy test, you may find yourself squinting at the test stick. In some cases, what looks like a positive pregnancy test result may actually be an evaporation line ...

Add Yahoo as a preferred source to see more of our stories on Google. Home pregnancy test results are only accurate within the first 10 minutes, so read results promptly to avoid misleading lines.

It is critical to distinguish a faint positive line from an evaporation line, which is a false result. An evaporation line is colourless or looks like a grey shadow.

When you take a home pregnancy test, you'll see lines indicating your results. One line confirms the test is working (control line), and a second line shows if you're pregnant (test line). Any second ...