I had a lumpectomy and rads. When my 6 month mammogram was done they thought they saw new calcifications in the same breast. I had a stereootactic biopsy followed by a wide excisional biopsy ( which was like a second lumpectomy). So it can happen. Iwent for a second opinion and went on a close watch prtocol for a year and now my mammograms and MRI are normal. What I found out from my research is that sometimes second tumors can be there and they are so small they aren't found the first time. Until you talk to your docs it is hard to know. I know some people have had 2 lumpectomies in the same breast. Some people choose to have mastectomies and that is a good choice as well. You just have to know that a mastectomy is not a 100% guarantee that cancer won't recur because it can.
Did you have genetic testing done?
Hang in there Jennifer. It is OK to be worried and scared. I think all of us would be. Remember to take one step at a time and listen to your docs. And come here often and keep us up to date on how this all turns out. You are in my thoughts and prayers.