I remember years back, probably early 90s, I was back and forth every month for scans. They didn't seem to know what they were looking at and ultra sound scans were nowhere as sophisticated as they are now. They eventually decided it was 'changed breast tissue', but not cancerous. I've had a more serious scare a few years later, where I got the impression the consultant was convinced it was cancer from the mammogram, until he did the needle biopsy. He said with relief that he was 99% sure it didn't feel like a cancerous lump. He was right, but it was a worrying time.
I hope all is fine, but like many of us, empathise with how you are feeling.