My brother is on leave from Iraq right now and I really want him to see my baby before he goes back. My next OB appt isnt until after he is gone..so we've scheduled a 3D/4D exam with a local ultrasound facility. My hubby, parents, FIL, brother and SIL are all coming

They warned me that a gender determination might not be possible..which is Ok with me since I'm only a few weeks away from knowing anyways. However I was wondering if anyone HAS found out that early??? If you found out did they change the gender later on?
Thanks!