If you have a reasonably low body fat, it can be bloating from certain foods.
I know when I was on my strict diet, I never looked bloated, even at a higher weight and body fat percentage. This was because I was always eating clean food. Now with a more relaxed diet and consuming extra carbs, some days I wake up and think I'm pregnant, even though I'm sitting around 10-11% body fat. I usually feel this way after a dessert or something else with processed carbs.
What are you macros at the moment?