I agree with DanW11. Have you ever been known to sleepwalk? What's hard to know is if a physical sensation triggers a dream or if one is acting out a dream. My father acted out his dreams to the extreme. That can become serious and should not be taken lightly. Unless you sleepwalk, I wouldn't worry much. If you do, then I suggest agressive measures to keep yourself safe.
I think most of us have had the occasional potty dream, and I've attributed it to the mind creating a silly dream because of the physical sensation of the need to urinate. Before my sleep apnea was treated, I frequently had dreams about smothering, choking, etc. and would wake up struggling to breathe. I feel certain in my case the physical sensation came first. I do not have what my father had.
Does anyone observe you sleeping? It might be a good idea to keep a journal of your incidents as well things anyone else observes, as it might prove helpful should you ever need to be evaluated by a sleep doctor. Include in that journal things like if you'd had a particularly hard day prior, late dinner, not enough sleep the night before, etc. If a pattern emerges, maybe identifying some triggers could allow you to avoid them.
Sounds like you could have a very mild form of REM Sleep Disorder.