Crazy scale?

Last night I almost had a coronary when I weighed myself. I actually gained 3 more pounds!! (I am restraining the curse words I was spewing at the time)

I hadn't weighed myself in over a week, and was really hoping to see the numbers go down. That 3 pound gain was enough to get my ass back into gear again with the better eating. So today I had very sensible selections for each meal and made sure the portion sizes were correct and didn't have any seconds.

Now, here's my question - when I weighed myself tonight, I was 4.5 pounds lighter than last night!! Is my scale screwed up? Is it possible to lose that kind of weight in a day??

I hope tomorrow it's another 4 pounds less!! LOL