I took a equate blue dye test and took it apart after two min and it was negative but the dye was running

After I took the test apart the blue dye was running down the strip barely and when i came back to it 10 minutes later it had ran down all the way and there was a faint line where the positive should of been! Is that evaporation? Or should I retest? I'm confused and don't want to assume I'm pregnant yet....