I agree with Lori... call the RN but instead of the RN at the onc office call the RN at the surgeons office not the receptionist just ask to talk with the RN. You may have to wait for her to call you back but thats ok be patient for the call. When she calls back tell her about the concern and see what she thinks you need to do.. but by no means wait 3 weeks ok. Sometimes the doc don't like to tread on the other docs territory. Which I understand cause they could tell you something and the actual surgeon what was there and did your surgery knows what was done and may have different ideas, even if they all work together its best to ask the doc who did it.
I had a lumpectomy too in May 05, I get lumps in my site occasionally I ask my nurse practioner and she said sometimes you get fluid in the site or sometimes it will bleed alittle which she said is normal. My lump is soft but does hurt when I touch it. it comes and goes. I notice it more if I have used my arm alot that day, but by no means does this mean this is what is going on with you. So call the RN today tell her whats going on and ask for help, tell her everything, and tell her your very worried, let her know you need to have help right away, if only for peace of mind don't let her blow you off k..tell all your concerns no matter how little k. Oh have you been running a temp?? she may ask that too and if its red or hot to touch, how long its been there, ect. so be prepared to answer those questions. She may be interested in these because she wants to make sure its not infected.
Like everyone says be proactive in your care k.... and good luck tells us what she says k....skeeter1