Water Retention

Water retention can have a huge effect on your weight.
If your cortisol is high and you find a stress reliever in a big high-carb, high-salt meal, it’s plausible that you could gain several pounds of water just from that.
Most premenopausal women will naturally fluctuate several pounds up and down over the course of a month regardless of how much fat tissue they’re carrying.
Water weight can hide your weight-loss progress temporarily, but that doesn’t mean you’ve stalled.

If you’re losing at a moderate but sustainable pace of 1-2 pounds a week, water weight fluctuations could even disguise a couple weeks of steady losses.
It’s not the end of the world, and you won’t remember it in a year. Just keep on doing what works for you, and look forward to the “whoosh” when it drops off.