I weigh myself every day too and my weight varies a lot! I have stuck to plan 100% every day this week but my weight actually went up on Thursday and Friday. Yesterday it was the same as it was on Tuesday morning and today I've lost 2lbs.
Although I weigh myself a lot the only weigh in I count is the official weigh in at slimming world as I know that for the rest of the week my weight varies so much even when I'm perfect on plan.
There are also numerous threads on here from people who think that they've gained because of a mid week weigh and then have a positive result at weigh in.
I wouldn't really pay to much attention to what your scales say at the minute. Yes, they can be good as a guide but you won't know for sure until official weigh in day.