I feel your frustration. I was 20 when got pregnant and 21 when I had DS. I think everyone acted happy for us, but were secretly wondering what the hell we were thinking.
I don't think it's our age so much (DH was 25 when DS was born) but our financial situation. DH doesn't make much and I choose to stay home. We struggle a lot, but we have the necessities and we're happy. So, we got lots of "congrats" from family, but also lots of negative comments on our financial situation.
So DH is making even less now than he was before, but we're thinking of ttc #2 in 6 months or so. We have NOT told family we're thinking about #2. But they still manage to work it into conversation somehow. Like one morning I wasn't feeling well and my dad said, "I hope you're not pregnant. If you have anothe baby, you'll have to go onto welfare."
: Well, first of all, no we wouldn't have to "go on welfare". Babies don't cost us anything. I breastfeed, cloth diaper, co-sleep, and use hand-me-downs. All we'd have to buy is a second car seat and goodness knows you can get those cheap if you have to. Second of all, he should be happy about ANY grandchildren he has. It's not like he's supporting us.
And then there's the people who insist DS "needs" a brother or sister. That's just as annoying if you ask me.
When we do decide to ttc #2, we won't be telling anybody but DH's family (who would be supportive no matter what) and maybe a few friends. They don't need to know we're trying and they don't need to know if baby #2 was an accident or planned. That's personal information. They'll all be gushing over the new baby anyways, and will forget any negative thoughts they had about us having another baby very quickly.
Have your next baby whenever you want. No one needs to know how or why that baby came into the world. Don't tell people you're ttc and wait until a little further in the pregnancy to break the news. Then deliver the news with a huge smile and make it KNOWN you are thrilled about the pregnancy.