Hi, Diagnosed With Stage 2 Breast Cancer In Left Breast

Hi, diagnosed with Stage 2 breast cancer in left breast 2001. Had bilateral mastectomies (right propylactic. Had last flap both sides) chemo 8 & 32 radiation treatments. Tamoxifen / Arimidex 5 yrs. had implants taken out 3 years later as they had shifted. Had them put back in each breast. Had a mammogram, causing leakage in one implant. Had both removed again but had only the left implant put back in and tissue from elsewhere was taken & put in the right breast. This has been 2.5 years. Last week I had a breast exam & there are 3 large lumps at 6:30, 7:30 & 10. I have a mammogram & ultrasound in 2 days so after that I will have more definitive answers, but I don't understand where the tissue came from, I thought there was no breast tissue left. Anything you might have to say I would appreciate. Thank you.