Needing help.

I had my first ultrasound done by by Obgyn this morning and by my last period she said I should be 7 weeks 4 days. She didn't see any fetal pole and she said it's typically called a blighted ovum when the gestational sac grows but the baby isn't there anymore. She wants to see me back in 4 days for another ultrasound to see if there is a fetal pole. Has anyone experienced this? Has anyone went back and there was a fetal pole seen? Please give me advice if anyone has experienced this. Thanks.