8w1d by LMP, measuring 6w on ultrasound?

Has anyone had this happen? What was your experience? I had my first ultrasound (vaginal) today at what should be 8w1d by my LMP. The doctor saw a fetal pole and what he thought was a little blinking heart but he's not sure, and said it was measuring more like 6w than 8. I'm going back for a higher resolution ultrasound this afternoon but I'm obviously scared to death. Anyone with a similar experience? How did it turn out? I have had no bleeding whatsoever. Thanks y'all 💜