Advice needed

Allyson • Due 8/6/19 with 🌈 👶🏻

So I need some advice. My NT scan came back negative for everything but my MD (muscular dystrophy) came back as a 1 and 500 chance and genetic testing is recommended if it’s a boy. They basically would test me and my husband to see who carries the gene. What if neither of us are carriers? Why does 1 and 500 sound so high? We don’t find out the gender until our 20 week scan. They told me not to freak out but that’s now all I’m doing. HELP!