What do you think?

Benton • Married: 08/15/15. Son: 05/20/16. Daughter: 05/18/18

I went and got an elective ultrasound at 15w + 2d, as we wanted to announce the gender before a close cousin goes away for Basic Training. It took about 15 to 20 minutes for the lady to find out the gender, as our little one was shy and wiggly. We thought it was a boy, because we kept seeing a protrusion near then genital area, but she said it was just ambilical cord. She showed us the three lines (second picture, bright area, was more distinct on her screen) on the screen, and even mentioned some nub stuff, and announced our little one a girl. But still, it was earlier than recommended, so I wanted your opinions? Girl? Boy? Thank you!