February 29th!!

I will be 19 weeks an 6 days the day we find out the gender of our 2nd baby. I am so very excited an nervous. With my son it was easy she put the ultrasound on him an bam legs wide open an you could tell he was a boy. With this one I've had 2 other ultrasounds.(9weeks&13weeks) both time baby has kept legs tight together . I know you can't tell that early anyways but what if it's still doing that when we go to find out?? Anything I can do to get baby to cooperate?