rosie i am sorry, that is tough. I had to have a core biopsy done because there was a lump that was not there before I got pg. it was right where DS's corner of his mouth was tightest when he nursed and I kept saying that was probably it. long story short, they wanted to be sure it was ok so I got a biopsy that showed that it was just milk and blood from damage to the breast. Here is my two cents- make absolutely sure that whoever you see not only specializes in breasts but specializes in lactating breasts. This is huge bc lactating breasts can look different on an ultrasound and feel different etc. Also, if you have to have a procedure done, research the half life of whatever anesthetic they use. I pushed the doctor on what the half life was and while they told me I couldn't nurse on that side for 24 hours, the half life of what they used was something like 30 min to 2 hrs. the doctor couldn't explain the 24 hr limit. I did a lot of searching in the breastfeeding forum ( a wealth of knowledge) and it was definitely ok for me to nurse sooner, DS nursed on that side within 6-8 hrs of the procedure no problem. Feel free to search my posts, I think it was somewhere in march of 2010, or pm me or ask a question here, whatever :) also, if you have to get a biopsy, push for an ultrasound guided fine needle aspiration to get an idea of what it is before you do a core needle biopsy.
Sounds like you have already figured out it is an abcess though and I don't know how they treat it other than draining it. Are you sure the pus isn't just older thicker milk that has gotten stuck in there? that can get as thick as cheesy looking stringy stuff, crazy. I freaked out bc my baby got some bloody milk from me for a while after the biopsy but, best for him to get mamas milk and not such a big deal :) keep us posted about how it goes!