<p>1) Take a deep, deep breath.
2) Continue to do excellently in school.
3) Talk to your guidance counselor. Wonder how much the Chicago acceptance is worth to you, particularly when you start considering other options more.
4) When you send in your midyear report, consider sending in a short-ish letter about your accomplishments/why you still want to go to Chicago. I remember reading from last year that the admissions office will consider additional material added to files, but you don't want to barrage them with tons more material.</p>