clear margins after lumpectomy

had biospy at 3 different sites - top-front, lower, and from side.  Lumpectomy was done and left an incision from just under arm, horizontal towards nipple.  Margins were not clear in 2 areas from the lumpectomy and went back for breast excision to clear those two margins three days ago.  When I got home from surgery I noticed the breast excision was done through the incision on the top-front, not the incision where he did the lumpectomy.  My understanding and logical thinking says that since there were no markers he had to go in the same way so he will know which areas to go back and remove additional tissue to get clear margins.  I couldn't get the doctor on Friday since he wasn't on call, but called his office first-thing this morning and will see him later today.  Am I correct in thinking that the doctor has to go in the same way he went in to do the lumpectomy to clear any margin areas?