@lovemelrose
There's so much to take in and terminology that is not part of the everyday so concentration on what it actually does mean as well as......
This link from the BCNA website hopefully will help and also give you an opportunity to absorb and formulate questions for your next appointment
https://www.bcna.org.au/understanding-breast-cancer/what-is-breast-cancer/triple-negative-breast-cancer/https://www.bcna.org.au/resource/fact-sheet-breast-cancer-pathology/and there's also a group within that may interest you
https://onlinenetwork.bcna.org.au/group/10-young-womenTake care and take a deep breath as there's a lot to take in
Keep posting as there's always someone online that may relate to your question and help you out