Boy, Jen. I'm really trying heard to understand why this image looks so different from the others. There is a clear fork there but there also appears to be some motion so the tip is being distorted. Since this image is flipped from the others and a different tone, can I assume you pshopped it? Do you know what order the images were taken in?
I read a study last night about fetal gender determination where they measured the angle of the nub at the beginning of the exam and then at the end of the exam and it changed. Seems fetuses - both male and females - have erections. The angle can actually change by the minute!
The other images look very male based on this graphic:
See where the big arrows point? This is called the cranial or caudal notch. In a boy, the notch is above the phallus and in a girl, it is below.