Lisa, the pain could possibly be from a clip - though it's unlikely. The clips are incredibly thin pieces of wire, and one would have to be pressing directly on a nerve. Not to say it's impossible; just that it could be something else, hopefully something related to the healing process that'll resolve itself soon.

As for the infection - you say it's much deeper in the breast than the surface nodule they first examined. Has your doctor told you you have a deep infection, or is this something you're concluding on your own? I'm not getting a sense here of how much you've connected with your doctor over this; does s/he know about the deep pain, and the continued draining? Since we're not doctors here, simply well-read breast cancer survivors, I'd say you should call your doctor to discuss your concerns with the pain, as well as with the progress of treatment for the infection. Best of luck - hope you're feeling better soon.