How accurate are planned parenthood pregnancy tests?

It should tell you on the box or there may be a little slip of paper that came with it and it may be on there. I don't know what brand you have, but I purchased one last year and it said that the results were 99% accurate. I took it and got a positive result and it was accurate. Although, I do believe I remember reading that it is more likely for the test to give a False-positive rather than a false-negative if indeed it did give a false result.