K.K.
Sounds like you're preggers! That happened to me too. My first one was VERY light...I had to keep looking because I thought maybe I was imagining it, it was so light. But I kept taking tests over the next few days and they got darker. I still had a hard time believing it, I don't know why. I am 25 weeks preggers now!
Dollar Tree tests do work...I used a bunch of those...and the cheaper wal-mart ones. Congrats and good luck!