It's pretty much all up to the group that you took your test from. Some groups are very quick to turn things around and send things in electronically right after the exam session. Others may batch things up from several sessions and submit them at one time. It's also possible that there was an error of some kind on your submission (most likely not your error, but from the folks giving your exam) so it was rejected and needed to be resubmitted by them after correcting the error.
Just have some patience (yes, I know it's hard, I've been in that boat as well) and it will show up in the FCC ULS system. If it takes much more than a few weeks (wait at least a full 14 days though), you may want to check with the folks that ran your testing session to see what's holding things up.