Ya think 4 lb weight loss in first 3 days is water weight?

I started 1.5 pill on Monday and weighed myself again this morning (Wed), and I’m down 4 pounds! Um, I think this has to be water weight. I may have worn clothes on Monday on scale, and have been trying to not drink wine during the week :). Plus, I know weight varies each day so….

Did anyone lose a few pounds right off the bat and was it prob just water weight?