Ramzi theory really accurate?

So I posted a photo of my ultrasound on here the other day because I was having spotting. Someone commented and said it looks like a boy, and to be honest, it kind of bothers me because I feel like the surprise was completely taken away from me. I know it sounds childish that I’m bothered, but we honestly thought about not finding out the sex until birth because we know this is our last baby. Is there still a good chance that it may not be a boy or is the ramzi method/theory pretty accurate? I’m sure it’s just my crazy hormones that have me upset...😕