When you get your first bill (or be proactive and contact them first), contact the office in question, explain your situation and ask for a hardship application.
They will more than likely require you to submit proof of your income and expenses. Once this info is received, reviewed, approved or disapproved, you should be notified of their decision.
Personally, I would not wait to hear from them regarding the status of said application, contact them after a reasonable amount of time as passed.
If not approved, ask for a self pay rate (if not already given) and set up a payment plan that has been approved by them and will work for you both.
Let's say your hospital bill was approved and that amount was written off in full and you get a bill from another provider for the same date of service. You should mention to them that x hospital adjusted your account and ask that they do the same. Generally that office would contact the hospital or other provider to verify this information.
Sorry to hear about your Chicken Pox...I do hope you get better and soon. It got me in the 11th grade...
~Zig