ultrasounds

So I had my 27week ultrasound this morning, and the doctor asked me if I was having a girl. I said no on the 20 week scan you said boy but wasn't sure, so he tried to look today to confirm but baby wasn't cooperating and had his legs crossed and was really hard to tell. So I guess I'm asking if it was a girl and she had her legs crossed would it be easier to tell since you can see the 3 lines? Or should we just stick with it being a boy?