How can my girlfriend and I break the news to our parents?

[Nox b]

I am 20 years old and my girlfriend is 21 years old and we have just found out that she is pregnant. And to say the least we are scared to death to tell our parents. We are actually very capable of caring for the baby, we both have good jobs and some money saved up. We only have to tell my mom and her dad cause the other parents are not around anymore. Even though money and maturity are not an issue we still feel as our parents are not going to be very happy. That is why we need some advice on how to tell them. My girlfriend is very scared of my mom and does not want her to yell and get angry about this. We both still live with our parents because we wanted to save money and we are actually going to move in together in January and get married next August. I know we should just come straight out and tell them but I don't want the grandparents of our baby to be disappointed in us and not want anything to do with him/her. We just want to know a way to tell them that might not stir a craze. Thanks for any advice.