it is called a preminition. it is nothing to worry about. my family has had them all the time. my grandmother saw her grandmother crash a car into a tree and die. she told her mom and got the crap beaten out of her for what she said then 2 hours later the police were at their house informing them that everything my grandmother said had happened shortly after. i have them myself on occasion. i have dreamt wn event happening thay seemed extremely realistic and told my friends about it and then what i dreamt ended up happening to every detail.