Weight Fluctuation?

I just recently lost 8lbs, and weighed in at 205.4lbs, but now, after not recording my intake for about 2 days, my weight has increased to about 208.8lbs, and I was wondering, is it possible to gain 3lbs so quickly? I mean, I haven't been eating the best this week, but I certainly haven't been going over my limit. Has anyone else experienced this? Should I not worry as much, because weight tends to fluctuate?