It's possible to get a slight false positive line. Sometimes when the chemicals are mixing it can look like that for a while. The instructions usually say not to look at it for a certain amount of time, then it will be accurate for a certain window of time, then inaccurate again because the chemicals can mix and show a false positive again. I would give it another week or two and take a test again. I know that's an eternity when you think you might be pregnant.
Best of luck,