Ovulation Timing Question

Ashley • Astrophysicist TTC @ 33. Oliver & Alessa born/passed Sept 2008. Emma born Aug 2010. James stillborn Jan 2015. Sarah born Jan 2017.
Yesterday in the morning and evening I had obvious positive OPKs. Today I'm back to a faint (negative) test line. It's only been 24 hours. Does that mean I've already ovulated (yesterday) or that I'm ovulating today? Pics below for reference. Trying to figure out when I'm starting the 2WW.