OK, a few questions here, I'll try to help with what I know.
Firstly, it is possible that you may have still done the bd in time, but generally EWCM is a sign of impending O. If your EWCM has dried up it is more than likely a sign that the fertile window is finished. It is generally considered better to bd BEFORE you O (or even before you see EWCM) so that there are sperm there waiting for the egg to drop, rather than bd after the event and try to catch it then. Sperm can live for up to 5 days in the right conditions whilst the egg only lives for 12 - 24 hours.
Secondly, cervical mucus and cervical position are only what are called secondary signs of ovulation. You can have EWCM and not ovulate, and you can ovulate and yet not actually see EWCM. The only sure signs that you have ovulated are taking your temperatures (BBT), blood tests, or pregnancy.
If you don't want to temp etc, then next month, be sure to BD when your CM is watery or EWCM. That is the most fertile CM and is more likely to see you get a BFP.
Hope that helps.
Lisa