I was using a dial scale so last night I bought a digital scale, turns out the old scale was 10 lbs off. I weigh 10 lbs more than I thought! I have still lost 11 lbs though, I am just surprised I gained about 50 lbs in 3 months!!
You really can't compare weights from different scales. You're right that you've still lost 11 lbs, but you can't really know how much you gained before, since you never had to chance to weigh yourself back then on your new scale.
Remember that weight isn't everything though. It's about how you look and feel. It's about fitness and confidence and how clothes fit. Weight's a good quick progress indicator, but it is still an indicator. Check some photos, measure and weigh to track your progress. scales aren't as reliable as how you feel so don't sweat it.
I strongly dislike digital scales. I hate the way all scales weigh different. You could line up 10 sets of scales and not weigh the same on any of them.
It may be disapointing but you can't compare yourself to others I mean you are upset because you weigh more than you thought but that is just a number you have still been the same size and weight and now you way less! Its awesome that you have lost 11 lbs!