Babys gender right or wrong??

So I'm almost 23, I am pregnant with my 3rd baby im not sure that the ultrasound tech was right with babys gender I have a daughter who will be 2 next week and a son who will be 1 in April. She told me baby number 3 is a boy but when I look at my other kids ultrasound pictures it looks more like a girl then a boy and I am wondering if she may have gotten it wrong baby would not hold still and keep moving. I'm happy either way just curious.