No fetal heart rate at 11weeks pregnancy

This is my first pregnancy. I had a vaginal ultrasound at 6weeks and doctor said that everything is absolutely perfect and the fetal heart rate was also perfect. I have been using folic acid and duphaston/progesterone capsules daily since my 5th week. I also had all symptoms of a first trimester pregnant woman. Yesterday I turned 11 weeks and went to get my NT scan done, and was very excited to see my baby's heartbeat. But the report says that my baby is just 6 weeks and 3 days old whereas it should be 10 weeks ideally. She said that there is no growth and no heartbeat. I'm feeling very devastated. How can this happen? My pregnancy was progressing very fine till my last checkup and now this happened. I had been taking healthy food, good care and proper medicines. There is no history of miscarriage in my family. I feel +ve about my next pregnancy but this pain is killing me. I have cramps in my lower abdomen and seen light spotting yesterday. Can I have any hope about this pregnancy?plz