I know it must be discouraging, but I have had that happen before when I buy a new scale. It might not be an actual gain, just the new scale measuring differently. Don't let it get you down too much. It's a new starting point, and you will know better next week, when you can compare weights from the same scale.
Stick with the same scales!!! And keep them in the same spot on the floor!!!!!That said...keep pushing forward and you'll see the numbers drop on the scales next week!!!