Two sacs one appears empty

I had a 6 week private scan. I thought 6w 3d. They sonographer did a transvaginal ultrasound and saw two sacs. One had a yolk, fetal pole and heartbeat measuring 6w1d. The other was slightly smaller and appeared empty. The sonographer said it was a 'possible blighted ovum' but said no more. I have a tilted uterus, could this effect it? Is there a chance? Has anyone else had this and ended up with two healthy babies at 12 week scan? Or am I clutching at straws...