3/4d ultrasound help

Marissa
We are almost 27 weeks and having our 3/4d ultrasound Saturday morning. They told me to drink something sugary before hand. So far the baby moves certain times of the day and when I lay down at night. I haven't noticed her moving after I eat or drink things. Any suggestions on what I should eat? 
Last ultrasound the doctor did she was curled up most the time and it was a struggle to find out she was a girl. I don't want that to happen again, since we are paying for it.