I have an old (2007) EPT Certainty Pregnancy test, not digital. I tried it today and I don't know how to interpret the results and i already threw away the instructions. There is a long retangular window and a circle with a line through it. When I tested only one line showed up and the circle is kind of light blue....do you know what that means? Are there suppossed to be two lines if positive?? thank you.