Waiting for Lumpectomy- confusing results

Greetings!

I received an ultra sound for a mass in my breast right under my nipple. I wasn't given any results and then whisked away to have a mammogram. Minutes later, it was suggested I have a core needle biopsy immediately. Within minutes I was prepped and had the biopsy. While it was nice to have everything done so quickly, it has my mind reeling- and no one would tell me why this is such an emergency. The radiologist only said the mass was "concerning".

Results came back from everything (below) and it was determined I needed to meet with a surgeon to have the mass removed completely.

Ultra Sound results: large, ill defined mass centrally within the breast, extending slightly lateral in the sub areolar distribution measuring 3.2 x 2.1 cm. This is concerning for malignancy.

Mammogram results: bi rad 4, extremely dense breast tissue (I am 30). Obscured large mass like density, ill defined mass.

Biopsy results: clinical breast mass, fibrosis with chronic mastitis, negative for identifiable malignancy.

I met with a surgeon two weeks later and he really tried everything to come up with a reason to not do surgery. He doesn't understand how different each result is. He said if it was mastitis, the mass would hurt. It does not. He said it is very rare for a 30 year old who has never been pregnant or breastfed to have mastitis. He determined the mass needs to be removed sooner rather than later. I am scheduled for Feb 7 for the lumpectomy, but his office will call if there is a cancelation. They tried to get me in the next week, but the hospital is booked.

The surgeon gave me a lot more information and answered my questions honestly. He went over next steps if the tumor is cancer. When I asked why he thinks the mass is cancer, he told me he doesn't think it is cancer because I am 30. The only reason he doesn't think it is cancer is because I am 30.

Should I be extremely concerned? Only family history is my paternal grandmother had breast cancer. My friends and family all say it is benign and not to worry. I consider myself to be extremely rational and know I need to wait until the lumpectomy results, but my heart just needs some guidance.

Thank you, friends!