Here are just some things that can make the scale spike (and it could do that several times a week, so get used to it, track your weekly average instead of a "weigh in day", or stop weighing yourself

)
- TOM, before, during, and/or after, depends on the person
- weight lifting or any hard workout
- high sodium and/or not enough water consumption
- starchy carbs (for me, anyway)
- random freakish bodily fluid production (which means, for no reason I can understand!)
I'm a daily weigher, but I've learned not to let that daily number be the boss of me. I track those daily weights, and once a week, I add them up, divide by 7, and see what my number is. Compared week to week, that's a more reliable number than a one-day dip or spike, so it lets me see the trend, week to week. If it goes down even 0.2 lbs for the week, I know I'm losing something, somewhere, dangit!