Following up without being pushy

I sent a proposal to a potential client six days ago and haven't heard back yet. I don't want to seem impatient, but I can't just let it disappear. I'm just circling back on the proposal I sent last week to see if you've had a chance to review it. I wanted to check in on whether we're making progress. No pressure, but it would help me plan my schedule if I knew where things stood. When you get a c