In the same boat. I've had cramping and heavy spotting all day. I've been on IVFC (lurked in your thread) and I know there are instances where cramping and spotting around beta do turn out well, but I suspect they almost always don't. We're prepared for the worst. I haven't tested because I want to hold on to the faint hope until the end, but I'm fully expecting the call to be from the doctor tomorrow (nurses do the + calls, doctors do the - at our clinic).
I'm not sure what we'll do next. Take a break most likely. Regroup and ask ourselves if we want one more kick at the can, or move to adoption. Or accept that we have a pretty awesome life as it is (I'm not there yet).
This sh!t sucks, man.
I'll be thinking of you tomorrow. Was hoping against hope for you that you'd beat the odds.