Definitely possible. Additionally, a few pounds can just be water weight or hormonal fluctuations too. It could also be from fluid for your muscles. Myfitnesspal.com has some good information on this, most notably here.

I personally don't find weighing ones self to be an accurate reflection of the work done (my family doesn't even own a scale). When trying to lose/gain weight, progress pictures can be immensely helpful. Most of all, I find that how you feel is one of the best measuring tools. I'm always in more consistently better moods when I workout, or working out can lift me outta a bad mood - if I bother to get up and just do it.
Mod CG since '09. CG as of 02/27/14.
Medium texture, normal-low porosity, normal elasticity and density
Products: VO5 KL (co-wash), GVPCB (RO/DT), SN (RO/LI), KCCC/BRHG/AVG (stylers)
Techniques: Mod-IceQueen, Plopping (FST), Octopus clip roots, SOTC; Double pineapple