I dont know. I had NO lump. Even after they knew it was there, they couldn't feel a lump. My attitude was always, It is what it is, just take one day, one step at a time and we'll get through it. Don't worry because if it is then you'll take care of it. If it isn't, then you've worried for nothing.
Hard to do, but just try to relax. Don't dwell on it. Deal with it when you have to, not right now.