LadyWee In my case, I didn't have "pain". I could feel something which felt like a lump and I could sense something inside my breast, which felt like a pea. If I pressed against that part of my breast, there was a sensation - I wouldn't describe it as pain, but I could definitely feel something and that's what I described to the GP.
I waited patiently for my routine mammogram, which confirmed there had been changes. I was recalled at that point and had an ultrasound, which showed up a lump. Fortunately, it's still small (11mm), but is not a sebaceous cyst, which I've had before. I've now had a biopsy. It will be removed, whether or not it's cancerous.
LadyWee I wasn't relying on advice from GN. I had read the same as you posted. I had an unexplained lump (without pain), which the consultant at the breast team told me should have prompted a referral. He still couldn't fell anything, although I could and should have been believed. The point is that the GP couldn't feel anything when she examined me and didn't believe me when I said that I could. She obviously dismissed me as some kind of fantasist or hypochondriac.