I'm 23 Years Old And Husband 28. Married For 3

I'm 23 years old and husband 28. Married for 3 years.I got pregnant with IUI.During my 7 weeks scanning doctor said heartbeat is seen and growth is normal.my blood test and urine test results was also normal.As per doctors advice took fertigyn for alternative 5 days for 3 months. Now i am supposed to be 13 weeks had done scanning again and doctor said there is no heartbeat and growth is stopped at 9 weeks. What could be the reason for this? Is there any hope if i wait?If i concieve again will it happen again?