1/2 day period

Abbey

Has anyone had a “period” last only about half a day? I got what I thought was my period yesterday morning, put a tampon in and when I went to change it early morning there was barely anything. Then I went around lunchtime and there was nothing. I haven’t had a tampon in since and no blood whatsoever. What could it be? I ovulated 16 days ago according to the app so it’s past the window of IB. Thanks for your help!