Increased risk for Downs results

We got results back today for our twins (12 weeks tmrw). One came back with an increased chance of Down syndrome. 30/100 chance. Going to a fetal doctor Thursday for more testing. But we are freaking out, doing our best to stay positive until we get more information. We are first time parents, I’m only 33 so I really wasn’t expecting this. Has anyone had experience with false positives on NIPT tests?