Further song than expected...

Masha

So today I went to planned parenthood to basically confirm my pregnancy and see how far along I was, I got an ultrasound and it turns out I’m 4 days further along than what I would have been based on period calculation. 6 weeks and 3 days, and here’s my little tadpole! Could someone please explain to me all the letters and numbers on the side of the ultrasound and what it means? It’s a little confusing. 😅