This is what I've noticed. When TOM hits, within a day I "lose" the water weight. The week to 2 weeks following is when I see weight loss. Then mid cycle, I see a gain. After about 4-5 days, I can usually see that weight loss come off, and get back to the weight before the water gain. But then after a few days, I see a little gain that just stays until after TOM, then I see the water loss, and real weight loss.
My guess is I am slowly losing during the second half of TOM, at the same time I am slowly "gaining" water weight leading up to TOM, but since I'm also losing real weight, it shows up as this plateau I usually see a week or so before TOM. Then when the water weight come off aftee TOM I get an accurate reading.
I've heard other women express this as well. But for years I really wasn't getting it, and I thought I was gaining weight and didnt know why, or I wasn't losing despite being on plan...It drove me nuts.
Of course if I were to have a huge meal one night or something super salty, I'd see a little issue, but it would only last for a day for me. (like I'd see it in the morning when I weigh)
Now that I understand how my body works, weighing daily is not a abd thing for me, as it once was when I saw the numbers on the scale as a reflection of my eating habits.
If you track your weight and cycles for a few months, you will probably start to see a pattern. So in the future you will know that a gain is from your cycle and not something you did wrong. Also, I can now tell exactly when TOM is going to happen by the scale!