Where does the dye go on a test?

Rebecca • 27, TTC my second baby. I love my husband for giving me baby #1 who is the most amazing gift in the world!!
So on the strips you dip into a urine cup, where does the dye go? I know it travels along and if your pregnant that's what forms the like but if your not pregnant where does it go? Does it end up at the other under underneath the HCG sticker part?