20 week bad results

I had the 20 week screening done a couple days ago and found out there's fluid in my baby boys kidneys and heart and they're kind of concerned that it could be Down syndrome cause thoese two normally run together but I've always heard of many cases where this happens and baby not have ds . I'm only 18 so I'm think the chance could be slim but has anyone else had this and it resolve itself or had any problems with it ? They told me it could resolve because it's still early but I  scheduled for a level two screening .. Advice to free my mind please .