H.W.
Please, don't beat yourself up over this. The egg is protecting what's inside during ovulation and for the first few weeks afterward. I have known quite a few very responsible women who had a blighted ovum pregnancies. It might help for you to do research. Or talk to a therapist, someone who deals with pregnancy loss. They are out there; your doctor can likely refer you to someone who specializes in this. Miscarriage is a traumatic event for some of us. It actually got me into therapy when I was younger, and helped us sort out our own feelings. But please, don't blame yourself.