I'm twenty-one as well. DH and I got married in 2009 (I was twenty at the time). I don't regret it for a second, but also realize it's not for everyone!! :)
I don't know the lady who said that to you, but it's quite possible she was just teasing you. I know my family (grandma, mom, sister, etc) constantly ask when we're going to have a baby. I laugh when they ask and enjoy their questions and interest, but tell them it will be at least another year or two! :)