Here are what I have got from the site with my visa checking:

 Your visa case is currently undergoing necessary administrative processing. This processing can take several weeks. Please follow any instructions provided by the Consular Officer at the time of your interview. If further information is needed, you will be contacted. If your visa application is approved, it will be processed and mailed/available within two business days.Why my visa is undergoing admnistrative processing while I was being told that I am passed when I finished the interview.