If you are under 35 & aren't experiencing any issues then it's completely normal to not have a scan til the morph one. It is becoming increasingly popular however for women under 35 to get the NT scan done.

If I had been under 35 when I was pregnant I don't think I would've had the NT one done. I was however 41 so felt it was necessary. By the time I went into labour I'd had 8 scans. Had I not had the NT one I would have only ended up having 4 scans in total as the others were a result of having it done.