Amazingly there aren't many people on here that know much about Ramzi simply because it is kind of a confusing theory. Honestly after all the pregnancies I've been through I've been studying Ramzi like crazy and I apologize ahead of time for the book. According to Ramzi if the baby implants on the left side of your uterus, it is a girl. If it implants on the right side, it is a boy. You can ask your tech which side of your uterus the baby is on but every time I asked that they looked at me funny lol. You can usually tell by ultrasound scans taken within 6-8 weeks what side it implants on if your tech doesn't give you an answer.
What throws a lot of people off is that they assume where the baby is floating at in the sac is where it implants but this isn't always true. A 6 week old baby is usually close to its placenta because the cord isn't developed yet but at 7-8 weeks the baby can float wherever it wants in the sac. You're not looking at where the baby is at in the sac... ignore the baby for now (I know... hard to do because you're so darned excited lol) but focus instead on the area surrounding the sac.
Another thing that confuses people is that a lot of ladies think that if it is abdominal scan, it is mirrored, and transvaginal it stays the same. Not always true. A transvaginal is looking at the baby from the bottom up (which is why the sac is usually flat on one side) while an abdominal is looking at the baby straight on. Mirrored means that the right side of the image is the left side of your uterus, and the left side of the image is the right side of your uterus. If you lay your scan picture on your belly with the blank side facing down and the picture side facing up, that is essentially how an ultrasound looks.
Now you must find your placenta. That is important to tell where the baby implanted. Remember... ignore the baby itself for now. Usually you can see a grey shaded area around the outside of the sac. If you look close you can see where it cuts off from the rest of the tissue in your uterus. This is your placenta. If the placenta is seen around the right side of the sac on your scan pic, you're having a girl. If the placenta is around the left side of the sac in the image, you're having a boy. If your baby implanted in the middle of the uterus and the placenta wraps around the entire top of the sac, you need to find the thickest part of the placenta and determine if it is more to the right or to the left of the image. Addominal images are almost always mirrored. Transvaginal needs to be flipped to the right to be mirrored.
I have attached a couple examples from my own pregnancies. I have included the location of the placenta (circled) and the original picture so you can kind of see where the placenta is located. The blue was a boy and the red was a girl.
HTH!