Did I test too Early??

My expected period start date was 9 days ago. I read somewhere you aren’t considered “late” until you are 5 days past your expected start date and your period isn’t “missed” until you are 6 weeks from your last period start date. Well I normally have a very faithful, on time or even early period so I took a test today and it was negative but I still haven’t started my period. Did I test too early??