Boy or Girl?

Well, everyone is asking me this same question for the past few weeks. Here it goes, on week 18, I did a scan, my doctor say 90% is girl. On week 20, I did a detail scan, this time the doctor say 101% is boy.. Who is who? It seems like the later scan is more accurate as the baby gets bigger and “thing” get clearer? Then again, is my monthly follow-up check again this saturday, so we shall see, confirm and double confirm?