Try taking an early response (FRER) with FMU. It should give you an accurate result.
Different tests have different sensitivities so may detect pregnancy at slightly different stages during early pregnancy (sometimes a few days apart)
well i was told it didnt matter if it was light pink or dark. i would go to the doc and have them do a test.
It may have been an evaporation line that looked like a positive, or the other test could have needed a higher level of hormone to show positive. Wait a few days and take another test, or get a blood test.