Ultrasound

Last Wednesday I went in for my first ultrasound. I was measuring 6 weeks and 1 day no fetal pole detected at the time or heart beat. Here I am a week later fetal pole and heart rate WAS detected but still only measuring 6w2days. My doctor said she doesn’t know what route this pregnancy could be going. Anyone else experience something similar. One again my anxiety level is on the rise my last period was May 11th meaning I should of been 8 weeks by now but I’m thinking I just ovulated later then I thought.