One day period/spotting

Amber • Mommy to Bryce 12/2/14 & Myla 5/29/17. Expecting baby #3 December 2019!
So my period was due Friday 9/16. My period is VERY regular. Well Thursday night when I went to the bathroom I had spotting in my underwear. It was enough for me to think AF was here so I threw on a pad and went to bed. Woke up Friday morning and nothing was on the pad. Put a tampon in Friday morning and every time I changed it nothing was there. Yesterday, nothing again, today nothing again. Idk if I should count this as a missed period or a one day period? I was planning on testing tomorrow. Has anyone experienced this? Is so what happened to you?