I wouldn't be nervous, but I would be concerned to have it checked. It seems to me that it is to just make sure that your changes are nothing serious. Did you let them know that you breast fed six months earlier? I didn't put down that I lost and then gained back and lost approx 10 pounds which made my pics look the same, but yet smaller than the previous year. So I was questioned about it. ANY slight change, they have to check..so take a deep breath, get it checked again and put your mind at ease.
Thanks! Do you think it could be from losing weight? Is that even possible? I hadn't nursed for 8 months before my first mammogram. But, I remember losing about 10 pounds a few months after. I think some of the pregnancy weight had held on for a while! I am definitely 10 pounds or so lighter than when I had that mammogram done. And at least a cup size smaller. Could that cause the changes?