When you were advancing the film for the first 11 photos, did you notice whether the rewind knob turned?
The best indication of correct loading, once the back is closed, is to take up the slack using the rewind lever (pretend you're rewinding, but don't press the rewind button on the bottom of the camera) and then after taking up the slack, advance the film and check whether the rewind knob turns. If film is advancing properly, then each time you wind the film, the rewind knob should turn.