The 2nd shot looks totally girl to me, I'm pretty sure I see three lines. The other two do look maybe boy, but unless that little penis is sticking straight up, I would think you'd be able to see it sticking out.
My boys were very obvious, although we didn't have their u/s until closer to 22 weeks. Dd was clearly a girl, there was nothing between her legs, just like pic #2.
Mama to 4 kiddos
5 angels in my heart always