I just wanted to second everything Meg said adding that depending on how you feel your parents will react, you may want to tell one at a time so that you'll have support with the difficult parent and/or if you have the type of parents who'll scream and yell before you've even finished speaking, maybe write a letter stating basically what Meg said earlier. Also, if you have specific plans of how you're going to handle the upcoming responsibilities, explain them to your folks, such as if you know of a particular school daycare program you'll sign up for, getting a job, getting good prenatal care, etc. Show them you're responsible and are willing and ready to take responsibility. As a parent, I'd be more supportive if I knew my child wanted not just to rely on me but was going to do what they could to help themselves. Too many girls think the government and the parents will handle everything. Show them you aren't one of those girls.