Ultrasound question

So I had a 2d scan and I asked the tech to check the gender , I'm 18 weeks and she was soo rude and said only come at 20 weeks for a gender scan, so I begged her to really check and she got frustrated and said the babies legs are closed and it wouldn't open all the way but she thinks it's 90 % girl! Should I relay on that ? Both times the baby wouldn't open its legs can it also be a boy? Even though I haven't seen anything sticking out