"Don't you think its too soon" "don't throw your life away, you already ruined it by getting preg" (that person no longer exists in my book) and such things.
Don't worry, I copped the exact same stuff from just about everyone... DH and I had only been together a month, and had just moved into our first apartment together (6 days) when DD was conceived (ON PURPOSE, I MIGHT ADD, yes call us crazy but we just knew it was going to work)... everyone was like, "Oh.. umm.. are you keeping it?' when we told them we were having a baby, my nana basically told me I was going to end up a single mum on welfare (because, I mean who would want to stay with me, right?), our friends were all sitting around taking bets on exactly how long we'd last...
Then when we decided to get married and we told my mum, she was like, 'Are you sure you want to make that kind of commitment?' Like, because having a baby together is a total walk in the park, you know... I figure we're already having a baby together, you can't get much more committed than that and even if we did break up later on, it would be no more difficult to get a divorce than it would be to just walk away from each other - there are kids involved now, it's a whole different ball game. So, we got married and eventually everybody came round, they were really apprehensive at first and just waiting for us to hit the skids but here we are, married nearly two years and expecting another baby and as happy as we've ever been... proved everybody wrong as hell and every day it just gets rubbed in their faces when they see how great we are together!

My fiance and I are seriously considering starting a family in the near future, I'm 20 in April, he'll be 22 in September, and one of the things that really holds me back is that in my mind "i'm too young" and I know exactly what my parents will say, as well as being afraid of what my friends and work are going to say...
Hun, don't you dare think for a minute that you'll ever be losing out by starting a family with the man you love. Having kids will change your life, and your life as a wife and mum will certainly be different to the life you've led up till now, but that doesn't mean you're 'throwing' anything away - you will be gaining a completely new and exciting life and I think you'd be hard-up to find anybody who would disagree! 'Too young' is completely irrelevant - I know 16-year-old mums who do a better job than some 30-year-olds I know, it's all about YOU and your state of mind and maturity.
I think today's society is far too wrapped up in selfishness and wanting everything for yourself, and not thinking about the long-term. DH and I always wanted to have our families young because things like career, travel and social life can wait! Holidaying iin Fiji, getting promotions and buying a house are things that will still be there when the kids are older, you only have one life so live it the way you want and don't let anybody tell you what you 'should' be doing with it! I personally wanted to have kids before I started out on my 'career', so that I could be at home with them while they were babies and then go and get a job when they started school, rather than only taking six months off and worrying constantly that somebody else would get my job while I was gone. I'm a totally different person to the girl I was before I had DD, but I haven't missed out on anything and I wouldn't change what I have now for anything.
Like I said, DH and I had only been dating for a month when DD was conceived, and we didn't care what our families and friends said because nobody except us knew the way we felt about each other and so we were the only two people who could say whether we were jumping into things too fast, or doing the right thing. Everybody said, 'Oh but what if it doesn't last?' but they don't think about the people they know who are together for ten years, then finally are 'ready' to get married, and end up divorced before their second wedding anniversary! Why waste time? If we don't work out, we don't work out, life goes on and we will always have those good memories and our flesh-and-blood reminders of the love we had for each other. And if things work out and we grow old and die together in a retirement home, then in everyone's face!!
I think parents will always be upset when you start your own family because it makes them realise that you're not their little baby anymore, you're a grown woman and you're going to make your own decisions... if they have done their job as parents right, they have nothing to worry about because you know what is right for you.