Make sure you read the directions carefully on your test before you take the test. With some of the tests, timing is pretty important. Some tests can show a false negative or positive if you've waited too long to read the test. You can get a false negative if you read too early.
The digital ones are pretty cool. I used one of those with my last pregnancy. Nothing complicated about them. With the lined ones, even a faint line means that you are pregnant...it just means that your hormone levels aren't as strong yet. Taking another one in a few days would give you a darker line and confirm your pregnancy.
If you think you got a bad test, just get another one. Almost any brand is ok, especially anything you pick up at a drugstore (I never really thought I should trust ones from the dollar store.)