First ultrasound Appointment but no baby

I was almost 12 weeks pregnant when I had my first vaginal ultrasound. When I went in, the sack was there but no baby. My doctor said I miscarried at some point but I never bled. Has anyone else had a similar experience?

Has anybody been able to have a full term pregnancy after blighted ovum? My doctor said I looked normal and healthy but not sure if blighted ovum was a sign of many more miscarriages