What is it a boy or a girl???? Need answeres please?

Im 20w 3d preggers and i went in for my ultrasound to see if i was having a girl or a boy and it took and hour for the tech to gather all the pictures she needed of the baby. it was 72 to be exact. Mind you my bladder is full and i had to pee so at this point im getting a little impatient, she finally tells me "Well from the only angle i can see, it looks like a girl because nothings there, Im sorry im not able to tell you for sure" I was so disappointed because i was ready to shop for the specific gender of the baby, gender neutral stuff can get so boring...Has this happened to anyone else and if so what did you do to find out the of your baby or did you just decide to wait til birth???