I tried for 9 years to get pregnant. I had fillings once with no novacaine just in case...

I am sure you will be fine, I don't think spina bifida is as prevalant as it use to be and it sounds like you got started on the vitamins pretty quick. down's syndrom is something you just can't help, my daughters best friends has a sister with downs, she is a lovely child, more work than a child without downs but she is loved and she is a real sweetie.