You appear to have something growing on your film. Do you live in a tropical region and/or is there any possibility the film might have gotten damp, e.g. refrigeration after unsealing the original foil packaging?

Have a close look at the neg and see if you can tell whether the additional density is silver or some other substance on the surface of the film.

Edit: that is definitely a film issue, not a camera issue unless you have a little rainforest going in there.