Breast development was painfully slow for me until a year into the process when I started taking Progesterone and I quickly went form a B to D cup. However just a couple months after starting Estrogen, my nips became these two super sensitive pressure points. One story I sometimes relate to others is that I was outside working one day, and a wasp landed on my chest. So without thinking, I gave it a hard swat,,. BAD idea. Oh the pain was awful,, :) Also, just a couple months along, I stated to secrete what appeared to be, Colostrum; It was clear and tasted sweet. I found it to be incredibly validating. Fortunately or not, it dried up a few months later,.