Definitely, no question... a boy :) As we began the ultrasound, the tech said, "Do you want to see if we can determine the sex today?" Of course, we said yes, and she added, "I will look, and then let you know towards the end of the scan what I determine."
But - it was too obvious to wait until the end. She measured everything... heart, brain, bladder, kidneys, limbs, and more. Then she got closer to his little butt and said, "Oh, yes - do you see that?" as she pointed on the screen. Before she could even say it, we knew! It was a boy. The scan lasted a good 45 minutes, and she revisited his private area 3 times to confirm, and each time, she said, "There it is... still a boy!" We have a couple of very obvious pictures of his private area as proof :)
We are having a son. We are shocked - I think Mr. D really thought it was a girl, and I think subconsciously, he convinced me the same. So, when we saw our little man's penis time and time again on the screen, each time we looked at each other in disbelief. We are both so, so, so excited - not only because we will be welcoming a little boy, but because all of his measurements were right on. Heartbeat was at 139 bpm, and he weighs 9 oz. I am measuring right on at 18 weeks, 6 days.
What a cool experience. I will never forget this day... I still can't believe we are pregnant, let alone know that our baby is a boy. I am on cloud nine.