Hi Jools12
My diagnosis, surgery and pathology was identical to you except I was PR-negative.
When it was discovered that I had a 3mm metastasis in one lymph node I was immediately offered an Oncotype test (no charge - I wonder where you are and why you have to pay for it?). The result that came back was in a grey area too but just over the line into chemo being beneficial. That was last year. I have had chemo, radiotherapy and am now on hormone therapy (anastrozole) and targeted therapy (ribociclib). I am doing well on these and although I was devastated and really unsure about having chemo but felt I might wish I had had it if the cancer came back. , I am now glad that I have thrown everything at the cancer. Chemo wasn’t easy but it is doable.
It’s not an easy decision at all and no certain right or wrong answer, but I’m sure you will reach the right one for you. I wish you well.
Thank you! I agree with everything you are saying no right or wrong you need to decide for yourself! I’m hoping seeing the oncologist will give me more info and help me decide! I’m so glad you’re recovering well done! 
ps I’m Scotland