Sex before marriage?

Hello Ladies,

I'm 19 years old and soon to be 20. My boyfriend and I have been together for almost 7 months now....and we've been very very intimate with each other. He and I had the talk about saving sex ONLY until we're married....but it's been so difficult. :'/ Has anyone of you ever had the same situation.....and really wanted sex before marriage? I made a promise to myself to never have sex until I'm married....and I'm scared that one day it may be broken. Have any of you broken this promise? How did you deal with it? Or if you didn't...what were ways that helped you get through it until you were married? I'm the only daughter in my family too....and I'm scared to bring shame to my family...if I ever got pregnant. I need some advice. :/