Sorry I disappeared.. I did my Christmas cards! You're probably gone now, but anyway... to answer your ?s:
No, we're not using OPKs, and I'm not even really monitoring CM to any extent. We're simply having lots and lots of sex. In a way, I'm considering this month a "break." After last cycle, I needed to step back from things a bit and refocus, anyway. I don't know... we'll see how I handle it!
Keep me posted on your twins!