Sex Advice?

Genesis

My boyfriend and I have been wanting to have sex for a while now. We are both 14, and I didn’t come here for a long paragraph on why I shouldn’t have sex because I am both emotionally and I think physically ready for this change. I have a problem though. I’m a very small girl and I’m kinda nervous if my boyfriend’s dick won’t fit my vaginal opening. And my parents don’t know I’m wanting to be sexually active and don’t have the guts to tell them. Any advice ? Thanks :)