NT scan showing liquid under neck.

I went today for my ultrasound, and left devastated!! My 12 week scan was showing a lot of liquid under my babies neck. I am seeing a specialist tomorrow, she didn't really explain to me much as she said it could mean a lot of things or nothing at all! My question is should I prepare for the worst, or has anyone else had this experience and their baby be completely fine?? Neither in my family or my husbands is their any genetic history, or abnormalities.