I would get the test. Its always good to be prepared for the Good and the Bad.
Just an example, the client i take care of is 12, and her mother did not get no testing done, and the child was serverly disabled at birth. It took the mom almost a year to get the appropriate help, information etc she needed for her disabled child. Some parents dont admit it, but raising a disabled child is physically and mentally draining, most parents feel it is there duty to take care of the child there self, but with all the new changes in the world, stress can be taking off the family, with daycare, in home nurses etc.
I wish you much luck and will keep you in my prayers for a healthy baby.
I agree with sweetangel7, in the small chance something is wrong it never hurts to be prepaired......and I did end up having to have an amnio when i was pregnant with my daughter (she turned out just fine and healthy) and I am glad that i had it done bc i would have worried about it the whole time if not....
I'd do the bloodwork, and then go for the ultrasound to check the nuchal translucency if you have abnormal levels. I know you will keep the baby either way BUT personally I think it is nice to know if there are going to be problems so that you can be better prepared etc. The test results are quick (within 2-3 days unless they outsource your bloodwork to another lab then it will take like a week...) Good luck!