Like what quincy has summed up, having ewcm or AF doesnt mean you O-ed.
It was “proven” in last cycle of mine. Last cycle was my first cycle after I’ve had an MC (so it was a little messed up). My body let out all the signs (was one the strongest I ever had), we BD-ed. But my temp never escalated in my BBT. After my EWCM dried up, one week later, I produced a lot of EWCM again. This time I did O, looking at the BBT temp shift. But we didn’t BD this round. And my mense was exceptionally longer than usual.