I've Had Nasal Polyps And Allergies For Years. The Other

I've had nasal polyps and allergies for years. The other day as I woke up in the middle of the night I reached for my water bottle because my mouth gets very dry, and as I took a drink, I felt something was at the back of my throat.......what fell out of my mouth was a huge oblong (about 3inches by 2 inches) piece of something. It shocked me. I think it fell out from a sinus cavity. It was semi-firm, smooth and sleek. It didn't look like it had been attached to anything. Could it be a huge mucus plug? Or what? Thanks