I Had Breast Cancer In 2003 Left Side, Ductal Carcinoma,

I had breast cancer in 2003 left side, ductal carcinoma, hormone positive and HER2 positive. I had a lumpectomy, followed by chemo & radiation & Tamoxifen. During my routine mammo this month, they found calcification groups on my right breast, and after a biopsy it is cancer. It is HER2 positive, but hormone negative. They are recommending lumpectomy, chemo with Herceptin and radiation treatments. After having breast cancer twice, I'm wondering if a bi-lateral mastectomy wouldn't be a better way to go. Would my chances of recurrence be better??