Lost 10lb in a week randomly

So I track my weight every Saturday to see progress and today I just saw that I had lost 10lb from my last check in. Is this normal ? Like I haven't changed anything no diet changes no gym changes so im so confuse. Especially since my last 4 check ins were in the same Weigh range no significant gains or loss and then boom I lose 10lb in 7 days. Has anyone seen this happen before? Should I see a doctor or am I over reacting?

Update: So I went to the doctor they said it could have been just massive weight fluctuation, and im back down to near my original weight this time, just 3 pounds less. So I'm not dying, which is great !