Did my dog break her tail?

my dog was on the couch and she fell backwards! she lnaded on her tail! SHE STARTED SCREAMING AND HOLLERING!! then she was circling herself because it hurt her. then she tried to sit on it and it didnt bother her. but when she walks it flabs and sometimes doesnt move. she would try to wiggle it but only from the center to the tip moves. did she break it?