I understand how you feel and I also agree with what everyone had said so far.
This will be my third child (next youngest is 9yrs old) and I think I have been stressing so much more with this one than I did with my other two kids. I think that because I have wanted this one for years and years and now it's finally happened as well as my age makes me feel quite anxious.
I over analyse every twinge, cramp and immediately jump to google...most of the time I find helpful answers from forums but then there are the not so good stories and statistics....I really need to stay away from google!
Life is full of uncertainties, failures and of course successes, it just needs to be decided as to which one you will focus on.
By feeling anxious we are actually focusing on the future which may or may not even happen and not focusing on the present (and at present we have the most amazing miracle going on inside us).
Each day we need to remember that miracle and embrace it, send it positive thoughts only, I know that these nine months seem to go so slow but really the time flies so fast. My DS will be 12 yrs old next month and I can still remember seeing that positive on the hpt for the first time, really doesn't seem like 12 yrs ago! But over that 12 yrs I have still stressed about everything to do with him, I always will (even when he eventually has his own family), I don't think that you will ever stop worrying about your kids, it's very much a part of being a mother.
As this will definitely be my last I have made it a point to try and enjoy every single day of this pregnancy, cramps and all! Much harder to do than say however!
All the very best with your LO and I hope you have a very long and joyful life together.