I second that. My mom does ultrasounds for a living and tells me there is a high false positive result for the AFP test. Maybe that's why my insurance won't cover it

. I'm debating whether I will do the test or not. With this test, positive results could mean something is wrong, or it could mean nothing at all and all is fine.
The next thing they will do is schedule you for a level 2 ultrasound (that's what my mom does) You should definitely do that. During that u/s, they will look for defects associated with your test results.
They can't see everything with an u/s (internal stuff etc) so even if the u/s is nomal they will probably offer you the amnioentisis. That is where they can for sure tell you if something is wrong or not. However there is a small risk of miscarriage when you have that test done. But it will tell you decisivly if something is wrong or not. I would weigh the options on the amnio test with your doctor. Make a list of questions and ask them all.