Yellow slip for B1/B2 visa category, need help


i had my interview on 11th of jan,2017 and they kept my passport after handling a yellow slip. when i asked is there any problem? they said no and according to my interview my visa is acceptable but they need some time to figure out whether to grant me visa or not, and did not ask for any documents and gave me a yellow slip with a case no. they also told me that i can check my visa status online and since then i have been checking and the status is ‘Administrative Processing’ and i am worried as i have my conference in feb. and i thought once i get the visa i will get my tickets done, but still no update can anyone help me out with this?