Almost 5 years out - could this be a recurrence?

I was diagnosed in February 2009 and have been going for mammos of the left (cancer) breast every six months. This time the radiologist saw "new linear and nonspecific calcifications in the upper outer quadrant of the left breast requiring further characterization". I am going for magnification views tomorrow.

This is the first post diagnosis mammo in almost 5 years that has shown anything unusual. This probably means nothing but the radiologist who read it is a different radiologist than the one who has read all the prior post-op mammos.

Has anyone else experienced this? Was it a recurrence? Of course, that's first and foremost in my mind.

Thanks.