We always tell people to ditch the scale because it doesn't tell the whole story. You could be going up in weight but down in size because you are gaining muscle - which is a great thing! Did you eat something that you normally don't eat? Did you have an "off day" where you kind of got off track? Did you consume salty foods? You could be retaining water! If you insist on weighing yourself and you just aren't going to give up the scale, only weigh yourself once a week and make sure it's on the same day and at the same time each week!
Because unless you have the same (experienced) person take them each time you will probably not get an accurate number, especially if you are trying to do it yourself. Most people do not measure in the same spot each time which can skew the numbers. If you must, we advise to only measure weekly at the MOST!
Again, what are you using to measure your "progress"...is it a number or is it a feeling? You also must be honest with yourself. Are you really giving it your all during your workouts? Are you skipping workouts or exercises within the workouts? Are you cutting your session short? Are you truly eating healthy? Are you grazing off your co-workers or children's plate?
Be PROUD of yourself and celebrate the small accomplishments! Small changes really do add up!
You can read about the "scale project" Whitney did here. She weighed herself everyday...find out what happened!