I agree with Aces. It doesn’t sound too out of the ordinary yet. You may have been doing this periodically in your life but it went unnoticed. Unless you have more issues I wouldn’t worry too much. I recommend prayer before bedtime if you are of the faith or setting intentions of protection. Keep us posted and we are here to help if something else happens.Your situation is something to pay attention to however it doesnt sound like you are in danger or have much to be concerned about. I would suggest keeping track of the nightmares and any other odd occurences.......then go from there.
You are right.....it could very well be due to stress. Only time will tell.
Light & Love
Btw welcome to the forum.