I understand what you're going through. I'm only 15 and I"m 5 weeks pregnant.
I told my Mom over the phone because I was too scared to tell her so I thought she would have more time to digest it.. But when I told her she cried, and she was upset with me but she mostly just wanted to help. So there was no need for telling her over the phone. I suggest you just come right out and tell your parents.