Hey hun.
I know this can be a really rough time, but you need to try to relax. Telling your parents really is the best thing to do. I know it can be hard. I was 16 when I got pregnant with my son. My mom wasn't the happiest person in the world, but eventually she came around and she was there when my son was born. I had a hard time telling her that I was pregnant again, at 17, but once again, she's started to come around. A good thing to do before you tell them is to have a plan. Figure out different ways you can finish school and all of that stuff. It will be hard, but not impossible. I'm still graduate with my class, on time, this May. So like I said, just relax. Sit them down and just flat out tell them. They will be mad, but they'll come around. Good luck.