17 weeks ultrasound "boy" correct or false?

I came in for a 17 week ultrasound today and the technician said that I am having a boy. I have a video of the session. But I heard that sometimes telling the sex before 20 weeks could be wrong. According to the video, do you believe that this is really a boy and not the umbilical cord?

I have multiple pictures, the first one is my vaginal ultrasound at 8 weeks. 

 17 weeks body

 17 weeks

here is my ultrasound 17 weeks video, I am not sure if it going to show up on here.

 Your 17 week potty shots look very promising for boy. 

Yep, that's a 

looks like a little turtle to me.... Boy!