I've been there, done that. I've weighed myself pre-pee and post-pee (Did you know that a good long pee weighs 1-2 pounds?!) I've weighed myself before meals and after meals, with wet hair and dry hair. It made me nuts! The truth is weight will fluctuate within 5 pounds so the goal is to get within 5 lbs of your ideal healthy weight.
What to do:
Weigh in 2-4 times a month in your underwear in the morning before you have eaten. Weight fluctuates slightly depending on the time of the month, if you are a woman, and other factors. How do you feel? How do your clothes fit? Get regular moderate amounts of exercise on a daily basis to keep unwanted pounds from creeping on. Ask your physician what your Body Mass Index is and learn the healthy weight range based on your height and frame.