Concern following ultrasound

Hi,

I am freaking out as I just had my yearly check-up and my GP called to say that a breast lump in my left breast was a bi-rad4 C: some history here, I have had a lump in my left breast for awhile and finally in 2017 had a biopsy done as it was flagged as a bi rad 4 A. A biopsy was done with 4 samples and deemed to be a fibroadenoma or fibroadenomatoid hyperplasia in fibrocystic changes. I was relieved. In 2018 I went for my annual check up and they noted a slight increase in size of the lump in the same location, but my GP said it was very minor and not a concern. Fast forward to 2019 and I had my check up a they seem to have seen a new mass in the same location. Th radiologist said it still looked consistent with a fibroadenom, so I came home reassured. My GP now called to say they have diagnosed this as Birad 4C. I am really worried. I thought fibroadenomas don’t become cancerous. I am otherwise completely healthy and have no history of BC in my family. Has this happened to anyone else? Unfortunately it’s all happening Friday evening so it isn’t till Monday that I can speak with my doctor again and get scheduled for another biopsy. Just looking for anyone with a similar story. Thanks in advance.