Posting in case it's helpful to others.
I've recently been diagnosed - I'm 49, and I have a 15mm grade 3 tumour and at least one positive lymph node, and am waiting for surgery (ER+, HER-). Feeling pretty miserable right now, but my main reason for posting is that I didn't go to the Drs when I first found the lump earlier in the year. This was partly because I had a whole load of other difficult stuff going on (serious family illness, two bereavements, teenagers needing support etc) and I just couldn't give it head space. But it was also because I managed to convince myself through selective googling that it was probably low risk - my lump is mildly painful, and gets more painful just before my period. (Most breast cancer tumours don't hurt, apparently). Also because it's right behind my nipple/areola, I decided it must be a blocked duct or some kind of cyst or infection. I think I even found an old thread on here where someone said that their Dr had told them you couldn't get breast cancer behind your nipple.