Confused with DCIS

Hello everyone, I had a lumpectomy on 17th December for DCIS. Pathology came back as Intermediate/High Grade, 20mm & ER/PR+. No lymph nodes where tested or the HER2 test. No invasion.

I saw the surgeon yesterday who says that all I need now is 4 weeks radiation. And it is upto me if I take tamoxifen or not.

I am wanting to hear other people's experiences with DCIS. The ladies in my support group all think that I should have a second opinion, as they all had either a sentinel node biopsy or several lymph nodes tested. 

I had requested a MRI but was told this wasn't necessary. 

My teatment is through the public health system and I wonder if further testing would have been done if I had gone privately.

Anyway, any advice from you ladies would be greatly appeciated.