I had a partial which is called lumpectomy and sentinel node biopsy which I think maybe what you are having. It is used to check if it has spread yes but as you are not having mastectomy first up sounds like they suspect contained to breast .Mine was clear so radiotherapy after - they only remove 2/3 nodes and done during lumpectomy. I was not clear on margins around tumour so went back to surgery to widen margins and came back clear. Is terrible the wait but hope you have bcna kit as great source information well worth it. Also many resources on bcna site - I found reading about it all helped a lot as does access to others going thru same. You are not alone and have support here