Also, a faint line is not common when you are about to start your period, a faint line means you are pregnant! As they say "a line is a line" no matter how faint.
Best of luck for the result you are hoping for.
You absolutely can test and should get an accurate result at this point.
You can, but chances are it will leave you with more questions. You may be convinced you can see a faint line (which can be common when you are getting ready to start a period), but because I've gone through this so many times before I know it will be hard to resist. If you have to take one, buy a 3-pack (that way you can wait a few days and take another), make sure it is the Early detection-type test, since you are still a few days from your expected period. Take the tests in the morning if you can; the best way is to urinate in a clean cup and follow the test instructions on how long to dip (as I'm dipping, I usually stir it to "soak up" any pregnancy hormones). Hope this all works out okay for you, good luck...
Try to wait atleast 5-7 days after a late period to take a pregnancy test. I know that is nerve wracking but you want the test to be able to pick it up if you are and even then it may not. Take it first thing in the morning as that urine is the most concentrated.