Young Pregnancy

I'm 17 and want a child. I'm still in high school (starting my senior year in two weeks) and I don't want to be pregnant in high school because I am a cheerleader and in color guard and I have FANTASTIC grades and I'm even going to college next fall for business management.... I have been with my boyfriend for over a year and I know it sounds stupid, but I really think he's the one. How do I get over this overwhelming motherly feeling? Ugh.