Google is very much a negative place. But I think Google does that just to highlight the dangers of anything. That way if someone is worried about something, after going onto Google, they'll most likely seek professional help.
I think if you want to see lovely success stories of most things, the best place is on t.v. and in magazines/newspapers.
Hun, twin pregnancies are extremely common these days, it's triplets and quads that prove dangerous. Like 'Baby Hospital' on t.v. the other night

Two of the triplets sadly died.
Also, any pregnancy can be dangerous, whether it be a genetic problem or complications with the pregnancy/birth itself. Nobody can tell any of us pregnant women if our babies are going to be healthy and well. Even if we get the all clear with blood tests and scans, there still could be complications with birth. I still haven't had my blood results back yet but that's not really my main concern, it's birth complications that concern me the most. In fact only til recently did I find out about the complications during birth and just how serious birth is. I thought the baby would just fly out but that's not always the case.
I hope I haven't scared you, you shouldn't be terrified like this though. Of course us pregnant women are worried but terrified we should not be. Billions of women have done all of this long before us.
Like the others have said, try to think about the positives! Your two little miracles are growing at an outstanding rate right now, and although we're the one's that guide them and nurture them, they still know what they're doing! Which is the amazing thing about pregnancy. Both you and I were their size once. It's truly fascinating.
I wish you all the best with your pregnancy and again, just try to relax.
And in the mean time stay off Google! It's good to get information out of the internet sometimes, but it can take over our sensibility too. If you're really worried about something, contact your doctor/midwife or come to us girls here. xxx