Lost 10 lbs in one day! What?

Mel
Every day I weigh myself to out in my daily update on this app. I had weighed myself this morning out of curiosity and came out to 139 and I just check tonight to update and I'm at 129! How is this possible to loose 10 lbs in one day with not vomiting or nausea, and I thought I ate too much today. Anyone ever had this problem??