Anyone else have swollen feet at 21 weeks?

Tonight I noticed my feet were swollen because my sandals got a bit too snug for comfort. I put them up for awhile and it went down, but why did this happen? I did Read online that it is possible to happen if it is really hot out or I've been on my feet for a long time but neither of those apply to my situation because I wasn't feeling too hot and I wasn't on my feet very long at all. Maybe my dinner was too salty? I feel perfectly find except my feet were swollen and now that has me stressing out 🙁. If you've experienced this please let me know