First ultrasound showing 2 weeks earlier

Hello ladies . I got a positive opk on July 9 and my vvvvfl BFP on July 20. Went today for my first ultrasound and should've been about 8 weeks going from my LMP (I had one June 22 but also June 1, it was my 1st and 2 AF after a missed miscarriage in march ) but the tech said I was measuring closer to 6 weeks . We saw a gestation sack and yolk and a small spec that could possible be the fetal pole but was too small to say for sure , no heart beat . I'm going in next week for another scan , has anyone been thru this or have thoughts ? I'm freaking out after my march loss 😔😔