Pregnant? Help!

So my last period was 10/31. I ovulated (I take OPKs) around 11/20-11/22. I got my positive around 12/3 or 12/4. I just left what should have been my 7 week ultrasound. The tech did a regular and vaginal. She said she couldn’t really see anything but there was something that “could be the very beginning stages of pregnancy.” But she couldn’t confirm anything and it definitely wasn’t what a 7 week ultrasound would look like. I have had a miscarriage before I had my 🌈. Can anyone give me some reassurance? Or advice? I go to the OB on Wednesday.