I Had A Lumpectomy To Breast In Sept 2015 And

I had a lumpectomy to breast in sept 2015 and oct 1 2015 then in November 2015 began 28 radiation treatments. my incision was in same place in both surgeries. meanwhile happened in february and now i had like a stitch that was sticking out I showed my oncologist she said put alcohol on it and it should desolve hopefully. It didn't and i sterilized the site and my tweezers and my husband pulled it out it looked like a hair folicle and looked like pus was on it. Then i put alcohol and neosporin on it a couple days then just alcohol. Today it looks like a pus site in that spot today. It sorta give weird sensations in that area. Do i have anything to worry about? It is small. But i can't understand why it even came about.