Before considering the way in which you want to tell the news to your parents, you should think about the timing: when to tell them that you are pregnant. The best answer is still: not too soon nor too late. Be patient and wait two or three months, just about the time it takes the embryo to settle. Once this period is over, you can safely announce it.
In order to make an original announcement to your parents, you can easily follow any of the suggestions on these web pages to make this event into a moving and exceptional experience.
You still have a few weeks time to devise your perfect announcement, so do take your time to find out what you like. You can draw inspiration from one or several different ideas and create the most touching, memorable and original announcement possible: your parents will certainly be moved to learn that you are pregnant.