I found a notebook and took that, but didn't need it.
I'm glad this story has a happy ending to it which I can leave here because the lump was indeed caused by menopause and not by cancer

I was scanned by ultrasound this time and she drew off a few ml of a pure white liquid for testing but she was fairly certain and the doctor even more certain that all I have is milk ducts in my right boob that decided to wake up and randomly produce some milk even though my youngest kid is now 23, so it's been a while since I was using milk from either boob.
The pain is less since she drew off some of the fluid, it was stuck there in the milk ducts getting thicker and gungier, my body didn't think it through.
So three weeks to the day after I noticed it, I have my answer for what was giving me a 2cm lump so suddenly. It feels like little water balloons in a bunch, she said they are in a line and as each one fills it flows into the next one so you can end up with a whole bunch filled together quickly.
She said it's always important to get these things checked, so if it changes, gets worse or happens on the other side I should still see my GP.
I'm glad I went and found out, it's called ducto-... I can't remember the rest of the word. They'll send a letter to me with the test results, but my goodness, it's exhausting, thinking you've cancer.