My first ultrasound

I had my first ultrasound a couple days ago, which placed me at 16 weeks. And surprisingly, I can actually make out a body: there’s a lump that seems to be the head, and another lump that seems to be the body! And they’re attached! I don’t think I ever had this much luck deciphering an ultrasound before… The techinician will be like, “Here’s the head… and here’s a leg… and look, there’s the heartbeat…” and I nod and smile and can’t figure out for the life of me how the heck she’s seeing these things. Sometime I wonder if she can’t figure it out either, and is just making things up as she goes along…