Is getting married at a young age a bad thing?

I’m 19 and my girlfriend is 18 we’ve been toghether for 3 years and are very in love with eachother. I know all of her flaws and grumpy attitudes and she knows mine.. The topic of marriage comes up from time to time and I just brush it off by say ” MOT untill we graduate college” but I sometimes I just think it would be great but then again maybe not so great! I know were in love thats not at question. Its just is of too soon to tell or what? How old were u wen u got married ( if ur married)