The tooth that gad fall out would be a supernumerary tooth...A supernumerary tooth is a xtra tooth apart from the tooth which should be there in the oral cavity...it looks like a normal tooth in shape and size..They are generally located behind the normal tooth but can found anywhere Buccal, Lingual, Palatal, Distal or Mesial... Now if it had fell of of its own....bloody ball may be just residual plugg which was left after tooth fell off..The plugg actually contains blood, soft tissue remnants .... I wud suggest you to visit a dentist so that he or she will curettage the socket...and clean wid betadine in order to avoid further infection. Hope this will help you...