I had the same procedure and still have my expanders, changeover date to be set next week hopefully. It will be quite painful so ensure you have regular pain relief and lots of pillows. You might even find sleeping in a recliner more comfortable for a while. I found by the 6 week mark I suddenly was much more comfortable and now feel quite good even though they are firm.
Here is a link with what might help to take to hospital. Hope all goes well and look forward to an update. Ask any questions no natter how small.
http://www.reclaimyourcurves.org.au/information-sheets.html