First ultrasound

Today I had my first u/s. They're going off my LMP to determine due date, even though I told them it's not accurate because I had a 31 day cycle. So according to their method I'm 6 weeks today, but she said it was too early to date and OB will let me know how far along I am. I didn't even get pics :( She labeled the gestational and yolk sacs so I don't get it. I feel like it was kind of a waste of time.