That could be it, to. It takes a bit to get used to it, i know. just keep it up, and give it a little time. :)
Yeah, i know, I have the same problem. I've tried a lot of things, and suffered a lot of failures (I gained weight on jenny craig, following their meal plan. ..yeah.) my knees are messed up, and I need to take some of the pressure off of them, so..
Good luck honey, and I hope your body adjusts to the change in diet soon. :)