We lost our first at 12weeks so we were very anxious to start with this time, although deep down I knew it was meant to be and had a good feeling. As above we had a viability scan at 8 weeks and that really did help.
The anxious feeling never really goes as things can happen no matter how far along you are (obviously the risk is less and less as time goes on), and then if the birth goes well etc but It's only the same as every day life, no matter what you do there's always a possibility of something happening.
But that's really just the start lol, as soon as they arrive you will be anxious of them breathing, being healthy, feeding enough, feeding too much, gaining the right weight, using the right products, worrying if you doing things correctly, developing and hitting milestones on time, pooping regularly and normally, weaning and the rest of it.
All I can suggest is to RELAX and enjoy it. There's no telling how things will go, what will be will be though mostly everything is just fine, and stressing about 'what if's ' won't help anything.
Take it as it comes, enjoy the pregnancy as it passes so quickly, and just try to think positively. Your pregnant right now which alone is a GOOD and positive thing as many never even get to that point, so just relax and let it happen

So on the whole and already being anxious, welcome to parenthood!!
(it's absolutely worth every second!!!)