16 week doctor's appointment and BIG ultrasound scheduled!

I went to the doctor's yesterday for my 16 week appointment, very uneventful. They took my blood, which made me woosy. The baby's heart beat was 152 BPM, which is lower than it has been but still great. No ultrasound this time no matter how hard I tried. I gained a pound in the past month which is great, at least I'm not losing anymore! At first they scheduled my big gender ultrasound for the 16th of August, but I called back this morning and got them to change it to the 9th at 9! So excited! What do you think, boy or girl?