Did the school who accepted you use Certiphi? I'm not completely sure how this works, but AMCAS checkout gives you that notification 'One or more of the schools you selected uses Certiphi background check (or something)...' which makes me think that not all schools do. This could be completely wrong though. Either way, I don't think you're in trouble.
While writing this, I saw this thread recommended which might answer your question:
Have people received certiphi yet?