The local anesthetic stings when it's injected but its not very painful. I had two kinds of breast biopsies. One was a stereotactic (mammographically guided) breast biopsy and another was a needle biopsy. The steriotactic biopsy was much more involved and painful than the needle biopsy which was over before I knew it. The thing that hurt the most with the stereotactic biopsy was the position that I had to lay in (with my neck in an awkward position) for a long time. My neck hurt worse than my breast.

I'm so sorry you have to have a biopsy. I hope it turns out benign. Best of luck.