Lump that can be felt but not seen. Im confused

Ninaamira

hi. I would like some input to my situation. A year ago I felt a lump on my left breast. It felt soft, movable and I was able to measure it using my index finger and middle finger (it fit right in between). If i was to describe it, it feels like a small (smooth) chicken breast and i can move it a bit. I can feel it more with my arm up. I had an ultRasound and a breast surgeon felt it but she wasnt concerend and told me to stop feeling it because I was doing that every hour. So I completely stopped, and fast forward a year later I still feel it and nothing shows up on imaging (ultrasound and mammo). Im very confused by all this. I feel that it has gotten a bit bigger but i just dont know what else to do. I have to separate my index and middle finger a bit more to feel it move up and down. All of this is giving me stress. Any advise? Is this Normal