I recently developed a cyst on my shoulder blade. It got bigger and bigger, and one day it sort of popped. I pressed on it (trying to turn it towards the mirror) and more came out. This went on for about a week. I'd shower, it would drain a little, then I'd wipe it with H2O2 or rubbing alcohol and put a band aid on it with anti-biotic ointment and acne spot cream mixed together until the next time I showered. At this point, it's still there, much smaller, but doesn't bother me. I'm sure at some point, I'll go through all that again and maybe eventually I'll have the thing surgically removed so it stops coming back. I think the best thing you can do is keep it as clean as possible until you can talk to a doctor about it.