Kinda confused.

Im using CB advanced. I started testing on CD 12, that morning I woke up with EWCM and had cramping like I was ovulating when I took the test it was a empty smiley (yes I know when you first test the test will be negative because it needs a base line) the next day I continued with EWCM and small cramps and I received a flashing smiley. I’m know in day 5 of a flashing smiley but all the cm is gone I’m practically dry. So my question is. Could I have tested too last and missed my O but still be getting flashing smiles??