I absolutely know how you feel even though we had our third when I was in my early thirties. My girls were 6 & 8 when baby boy Samuel was born. (what a joy

) but I was much more worried in that pregnancy than in the previous two. I have heard this is very common

. We are wiser than before and that is sometimes not good

We have heard more "stories" and then there is the whole "odds" thing which plays all kinds of tricks on your mind! It seems that with all of my friends they seemed to worry more with their last pregnancy than with their first! I completely agree with you about the testing. The false positives can also ruin a perfectly healthy pregnancy! Usually anything that needs to be treated at birth (heart or organ issue) is found in ultrasound. I wasn't one that could have prepared any better if I had known "something" was wrong. I would have just worried myself into a mess!
In the end I really regret letting those fears rob me of the joy of being pregnant. I was so convinced of something being wrong I forgot to enjoy the blessing of being pregnant!

He of course was and is a very healthy little boy.
If you have that hearts desire to grow your family remember this: God doesn't use "odds" to bless our life. What will be-will be. A baby that comes later is the sweetest reminder to slow down and appreciate every single moment especially as the older ones are growing up soooooo fast!
Blessings!