OB could not predict gender in 15.5 week ultrasound

Hello,
I had an appointment with my OB today and he always does an ultrasound in his office (a great perk!). I was hoping to find out some gender clues today but as usual... nothing!! I got a great shot of my baby in my 12 week ultrasound but no nub. I just can't catch a break! The suspense is killing me! Anyhow, I thought I saw a blob of something at one point in the crotch area but the bum was down against my uterus so he couldn't get between the legs for a potty shot. We only saw profile pictures. My question is, if it were a boy, do you think I would be able to see the penis sticking up from a profile shot?? Is a "blob" usually a penis? I realize these are kind of impossible questions to answer but I just need to talk to someone about it! xx