This is very normal and whether you have one child or ten...you will worry with each pregnancy. Try to relax and enjoy the life you're carrying inside and take care.
I am a father and I had those same worries when my wife was pregnant. As long as she is doing everything she can to stay healthy during pregnancy, as in not drinking, not taking drugs, etc, then more than likely everything will turn out fine.
It is normal for a soon to be parent to be worried about things like that. Don't worry, it can be common.
Of course we want our children to be healthy and remain healthy.
You just have to remember that if there were going to be any issues they would've been found and they haven't.
So it's likely that your baby will be in good health :)