Neural tube defects...

So my blood work came back positive for an increased chance of a neural tube defect. The original ultrasound didn't show anything concerning but the blood work came back with a 1 in 38 chance. So I'm going for another ultrasound this Thursday and possibly have to talk to a genetic counselor. This happened with my first pregnancy too and my son is completely healthy! So I'm trying not to freak out but of course I'm nervous. Anyone else have this test come back positive and everything was fine? On the bright side, at the ultrasound I am going to ask if they can tell me gender!!! So any thoughts, prayers, advice, experience, etc... Would be greatly appreciated!!