Make sure the time you weigh yourself is consistent, and the manner in which you weigh yourself is consistent. The most popular time to weigh seems to be in the morning, after using the bathroom, while nude.
Could be a slow loser. I generally lose at about 1lb a week average, which isn't so bad and does really add up. If I eat less carbs then I actually lose a bit more I've noticed, but I just adore my carbs and find cutting them out results bad things.
Worth noting that when I first began to drink an adequate amount of water during the day, I did hold onto that for a while. I think cause I'd been dehydrated for so long my body just held onto it for dear life. I'd probably wait a few weeks to see if there's still no change before changing anything up.