When you say blank, do you mean completely transparent, or completely black?

If the former, then the film hasn't been exposed or developed correctly - are there any edge markings visible, and is there a black leader? if there is quite literally nothing at all, then it hasn't been developed correctly (perhaps - if it is black and white film - it has gone through a colour process); if there is a black leader and edge markings, then there is perhaps a camera fault (shutter failure or wind-on failure)

If the latter, then it probably did get exposed when you unloaded it.