What if the testing line is very light in color, am I pregnant?

Yes. You should assume you are pregnant. The exact color of the lines is not important.

Though a positive result should not change for several days, a negative result may change to a false positive within minutes after the end of the testing period, which would not be an accurate reading. It is always best to read the results at the 5 minute testing period and then discard the test to avoid confusion