As long as it has colour and showed up within the proper time line (usually no later than 10 minutes) it's safe to assume that you are pregnant.
Its a positive :) congrats! Now call ur dr to make ur first appt
a second line no matter how light it is, is a positive, so congratulations at this point, when testing so early you do run the risk of a chemical pregnancy, so I would wait until your period is offically late and retest just to be sure, good luck :)