I know it's hard to tell your parents about any psychic abilities. The first thing you need to decide though is if you'll tell them, parents tend to believe what they want to hear so prepare for the worst, unless you have an understanding parent. This is what I told my parent:
I started by asking if they believe in psychic abilities, then I talked about how they discovered that in ancient times almost everyone could predict the future and that it was a natural instinct that slowly died down over the generations.
Then I told them about me being able to see the future from my dreams, at first they didn't believe, so I did what any determined person would do, do some research. After that you try again, try to make it sound "unjokish", as my my sister calls it, and shoot for an understanding.
If all else fails tell them how being a psychic is a gift from god, a gift to try to help people and warn them of any danger in the future, except maybe death because that would freak people out.
So even though telling your parents will be hard, you still have to try. You can't avoid it forever. For I have never known a single person who has been able to hide anything from their parents for more then a week or two. Never.