Hi Danielle,
Hopefully that won't happen.. I did not have sentinel node biopsy, but initial fine needle biopsy of breast and lymph node by US guidance. A week later I had the mastectomy and axiliary clearance of 22 lymph nodes. Only one of which came back as completely replaced with metastatic tissue.
I have had constant battles with cording in my arm and chest/abdomen since then, and over 8 sessions of laser therapy. The first 6 were over an hours drive away-a long way for Tasmanians!
You have given yourself the best chance of keeping your lymph nodes, so rest up in the knowledge that you have done all that you can do and surrender to the journey that unfolds.
I wish you all the best, the waiting is probably the hardest part.
Cheers Sonia :-)