I had my first one this year and was told right from the jump that often they need to do further imaging. And that if you have dense or fibrous tissue then you can almost guarantee you'll be coming back again. I am hoping that's all this will be for you too!
I have had to do this too, they actually did an ultrasound on the spot and I had to go back in 3 or 6 months for another ultrasound and mammogram, it ended up clearing up.
If it helps, they found one in mine when I was first diagnosed with cancer. It turned out it was crystallization which looks very similar on the mammogram and is a normal process of ageing. Try tot to think worst case x
I had to go back for more imaging on both breast for my first one because of dense breast tissue. so I am trying to keep that in mind but still because I am me and my brain hates me I can't help but worry