ah bless you, i sort of know how you feel, i am 9 weeks pregnant, this is my 5th pregnancy, my first i had to have a termination at 14 weeks due to problems with my baby then i had 2 misscarriges then a beautifull baby girl who is fit andn healthy, but people seem to think just cause i have a lovely girl that i will be fine this time, i on the other hand go through hell every day just waiting for a sign of problems, the only thing that i can say is go for it! i can say whole heartly that each pregnancy is different and allthogh it will be hard for you but if you have good support you will be fine. i just take each day as it comes.
wishing you all the very best.