Stupid question: which one is CD1?

Every month I get 2 days of spotting before AF makes her apperance. Still, I only log that my period started when it’s an actual...flow. This month I tracked ovulation with OPKs for the first time, got a positive on the 23rd and expected AF date was updated automatically to today. Like clockwork, I just started spotting but I am unsure if I mark this as my period starting or do I wait and do it like up until now. Really trying to do this tracking thing right so that maybeee next month will be our month ✨