We recommend weighing in every day! It is very normal for weight to fluctuate a lot from day today. Anywhere for 1-5 pounds for many people, and sometimes even more. To help with this, the most accurate way to know your "true" weight is to weigh yourself every day and get a weekly average. The good thing is, Carbon's got this handled for you! As long as you log your daily weights and enter your weight at check-in, Carbon will average them for you at check-in. We recommend weighing yourself at the same time each day for consistency.
We want to point out that it isn't always possible to weigh yourself every day, which is okay! This will not derail your progress. If you can only get 3 weights for the week, that will be better than just 1 at check-in.
To learn how to add, edit, and delete weigh-ins, see this article.