Thoughts on Engagement at 18

Myriah Rose Fuller • CNA ☄ strange little girl.
So my boyfriend and I have dated since sophomore year of high school and we're seniors about to graduate. I always come back to him even if I did something wrong and he never stops loving me and I the same. 
He proposed at prom, so we've been engaged for about two weeks. Everyone says we are too young, or asks if I'm pregnant. 
Do you guys think we're too young? I know college and careers but he always want us to be by each other's side. So.