I wouldn't worry too much! I'm pregnant with my first at 21 and I was still REALLY scared to tell my parents, so scared I told my Mum over the phone just before me and my OH went into the cinema so I could get off the phone...!
Thinking about it, I wish i'd have told her to her face as her response was nothing like I thought it'd be. She was a bit concerned at how we would afford a baby as we only bought our house in Oct 2009 but the next day she was pointing out prams! Lol!
You'll be absolutley fine sweetie!
Congratulations and good luck in telling the parentals!
Xx