Question for those with ultrasound/biopsy experience

Unicorn28

last week I had a mammogram that showed calcification and a mass. I had an ultrasound which showed a solid nodule which they categorized as a birads 3.

Yesterday I went for a consultation with a breast surgeon at a fantastic breast cancer center. They agreed to biopsy due to my anxiety. My biopsy was scheduled for today.

Today I went in for my ultrasound guided biopsy. When the doc eent in, it turned out to be fluid filled and she she said it ended up being a cyst!! Fantastic news!!

But my question--how could the ultrasound have showed a solid mass, but it ends up being a fluid filled cyst?? Am I crazy in worrying that the wrong spot was found and that solid nodule is still hanging out in there??