Sick Pay waiting period CA

I was just informed my new job has the 90-day waiting period before using sick pay.

I had to leave early because I got sick at work. I'm not finding any additional guidelines about how the waiting period works from the company or online. Can I retroactively submit for that hour once I hit 90 days? Or does the sick pay I am accruing only apply to time taken off after the 90 day mark?