I have a theory that fits this.
Originally Posted by chuck94022
The film didn't catch the takeup spool when first loaded... but after some 20-or-so shots, it FINALLY caught and started winding...
So it might have been good to go, but OP rewound and sent the film in for processing.
All good advice to check the wind knob is turning as the shooting progresses. Good to check that the camera can make it through a roll of scrap film when properly loaded... But chances are... Next time you shoot... You'll get a good roll of film.