Hourly chart shows the S&P 500 as range bound ahead of the Fed meeting. I posted longer term charts on Monday.
Don't waste time thinking about (guessing!) which way the market will move in response to whatever announcement or non announcement the Fed makes, instead think about levels and what you will do if the market hits those levels. Will the market break out of the range, and what will you do if it does? If you open a trade, how much will you risk? How will you manage that risk?