INPUT NEEDED

So today I had my first appointment today at what I thought was 7wks 2dys and I was diagnosed with BLIGHTED OVUM . I found out I was pregnant Dec 1 and my last menstrual cycle was Oct 27 . I had irregular periods so I really only track off the month and the month before when it comes to my ovulation date cause it could be anytime with my periods being irregular. They told me my options if in two weeks I dont see anything, but I think I should wait . My uterus measured out to some extent that I should be around 6 wks, but no sac no baby . Anybody go through this and what do you know about "misdiagnosed blighted ovum" . Thanks.