I know how you feel, kind of. Turns out my usual scale is under weighing me by about 8lbs compared to the doctor's scale... I asked for a weigh-in when I was there last week and felt like all my hard work had been undone in seconds
Like you say though, the amount you've lost is the same, and you've still got all the other benefits of what you've lost so far. I know it sounds trite when you look at the numbers, but I've been having to tell myself the same thing.