For various reasons, some of which you may never really find out, your case, you may get an update from the State Department that tells you your case is in "Administrative Processing", or AP. What that means in terms of immigration matters, is that there is something about your case that they don't like, so they're going to take a little longer to look at your case. This has increased in frequency since President Trump's "extreme vetting" doctrine, in which all cases generally take longer to process. It does not mean that the reason for your delay is due to more applicants in line. It does mean there is some peculiarity with your particular case that somebody wants to take a look at. Generally, this results in a delay of about 60 days or so.
It could be that they will send you an RFE, request for evidence, to ask for more information. It could be they're waiting on some kind of background check or other piece of external information as well. It's a common frustration to not know exactly what's going on and what they're looking into or waiting on. You'll just get notice that your case is in administrative processing. There's not much you can do about that other than "hurry up and wait" for them to update you or request some additional information from you. And if you do hear a request for something, you should be sure to respond precisely with the info requested, and go out of your way to produce the best version of that information you can, in a timely manner. They are basically looking for an excuse to refuse your case, so the burden is on you to convince them that there are no compelling reasons to deny your case.
While it's not good that you received an AP notice, as nobody wants to be delayed, at least you didn't get a denial. If your case was flat-out unapprovable, they would have just denied it, or issued an "Intent to Deny". So the fact that they're still considering the case and possibly waiting on more information at least indicates that your case still has a decent chance of moving forward. If they do request information from you, D=don't take any shortcuts, don't make excuses. Spend whatever you have to spend, do what you have do to get them exactly what they want. Give them a reason to release you from AP and get you approved.
