Something weird in my mouth?!

Around an hour ago, I was swallowing and it felt as if something solid, like a pill or something would get stuck. So haven just eaten I slid my finger down my tongue, right to it's base and felt a lil flap. Whenever I drink or swallow I feel this flap move and I'm really confused on what it can be. I've done a lot of research but to no avail. It's weird to think something like this can develop so quick..
Anyone experienced this or know what it might be?
Thanks a bunch