Been there and wish I could tell you something positive but I remember all too well the platitudes of my friends when I knew everyone else that interviewed at the same time were already moving forward.

That said it isn't over until the fat lady sings or in this case hits send on the email. Do you know if more than a few others that interviewed at the same time have all had references called? If you don't know about anyone else or just a couple people started getting calls you may still be OK.