Blighted Ovum?

We had an ultrasoundon Wednesday dating me 6+1 based on gestational sac measurements. Today, (6 days later) my ultrasound measures 6+6, however, we were unsuccessful in locating a fetus and we located a possible yolk sac. Because of this, and my hcg levels went from.14,000 last week to 19,000 as of Sunday, they are thinking it's a blighted ovum. Has anyone else experienced an empty ultrasound under 7 weeks and went on to have a healthy pregnancy? They stated there was a bleed on my gestationalsac last week, however, it resolved itself and the ultrasound shows no current bleeding. My cervical length went from 3.6 last week to 3.8 currently. I'm just trying to make sense of this.