Empty sac :(

Went into today for my 7 week scan only to find that it’s empty, no yolk, no embryo, and no heart beat💔 I am honestly so heart broken, I was so excited for this pregnancy this is just awful. This is my first ever pregnancy, it took over a year and it finally happened through fertility treatment. My doctor said i’m measuring a week behind. But even at 6 weeks wouldn’t you see something.... From what I googled it’s called blighted ovum. But i’ve also read some miracle success stories about women who their gestational sac was empty up until 9/10 weeks and then they finally saw baby was normal and healthy. Anyways I was hoping somebody would have any experience in this I would really appreciate it. I haven’t had any bleeding so far. Also please do not say maybe I am not as further along as I thought because I did fertility treatment and ovulation was controlled so they know exact dates. I should be 7 weeks right now.