Cervical mucus

Do you generally have raw egg white cm for a couple fertile days up to ovulation, or only once ovulation occurs. I always have it a few days every cycle but was unsure if the start of it is actual O day or if it’s just the body getting ready.

I know everyone is different. Just looking to see if anyone has noticed a correlation. My OPK didn’t quite look positive today so I’m unsure if it might be later tonight or if it is still a day or two away.

Thanks ladies!