Should I do Chemo?

I am a 48 year old female with an ER pos, PR pos, HER2 neg, 1.3cm tumor.  I had a lumpectomy w/ 5 nodules removed (clear margins and node negative).  My tumor grade is 3+2+1 = 6/9.  I also had two Genetic tests done.  BRCA1 was uncertain, BRCA2 negative, BART was negative.  But, my Oncotype score is 21, which puts me in the low-intermediate risk range.  

I will definitely do radiation and tamoxifen, but I don't know if I should do chemo.  Doesn't chemo have long term side affects (forget about losing your hair, I mean damage to other organs), etc.  As I understand it, there is only  3-4% chance that chemo will help me. What about nutrition?  Doesn't that play a very active role in reoccurance?

[Cleveland Clinic]

Dear Gina709, Decisions about treatment for breast cancer are based on a number of factors and ultimately the risks vs. benefits for the individual patient.  Over the internet on this forum we cannot give specific treatment recommendations.  This is something to discuss with a medical oncologist who can discuss the risks and benefits as they apply in context of your individual situation.