About in rapid ppd. Me a mistake result?

I dont feel anything wrong inside me and i know myself that i am healthy. Since last week that i got this pre screening test in clinic for employment international. Im working outside the country since 2006 and now i do have 4 months vacation the clinic that have test me told me that i do have latent tb since then i cannot slip. Is the rapid ppd test is the procedure that can detect if you have tb or dont have? Is rapid ppd test is test that they will check your blood or they will check your skin test. Im so very confusion? The clinic test my blood they told me that it was a rapid ppd test. And when i do check in the internet that rapid ppd is test for tge skin not in the blood? Is it true? I do get another doctors opinion about the latent tb result that the clinic told me so. and the result is negative. Is it possible that the clinic give me a mistake result? I do need answer.... plssssss..... i cannot sleep anymore thinking that i am sick and cannot travel abroad any more.