What to find out sex before the 27th

Ashlee • I'm married to my best friend. We have two kids earth side a boy and a girl. We have two angels babies. Were expecting our rainbow baby in October and were having another girl.
So me and hubby want to find out the gender of out little one. Hubby is most likely going to be out of town on the 27th for our appointment. I don't know if my dr will let me find out earlier than that now that we know he will most likely be out of town. I don't know where I can get another ultrasound to find out the sex either. We really want to know.