Am I ovulating earlier than predicted?

According to glow my fertile window starts today 20/09 but I’m confused because I think my fertile window stared on Wednesday 18/09. In the first pic is cm on Wednesday. This morning is was completely clear and stretchy, didn’t get a pic and this evening is pic 2. Please help😔 could I be ovulating earlier than predicted every month? I have a regular 28 day cycle