Vertical Oriented Solid Mass

I was wondering if I should be worried that I was given ACR Bi-Rads Category 4 for this lump that was found by ultrasound (not found with the mammogram).  I had gone in to get two other lumps checked and didn't even know about this one.  According to my report it says: 8mm vertically oriented hypoechoic slightly shadowing solid nodule.  I am really worried that it is breast cancer. They also rushed me into a specialist that I am seeing today and they are probably going to do the biopsy today as well.

[Cleveland Clinic]

Dear jojorisin,  A BIRADS  4 rating of an ultrasound or mammogram describes a suspicious looking abnormality that is not characteristic but has a reasonable probability of malignancy, and a biopsy should be considered.  In other words, based on the testing done they cannot rule out that something is cancer.  So to be on the safe side a biopsy of the suspicious area is recommended.  It is possible that this could be something benign (non-cancerous) but without biopsy confirmation we can’t say for sure.