I have five kids and 3 grandchildren, so far, and have never understood the perceived importance of knowing the child's sex in advance. M/F doesn't matter as far as importance and unless the parents themselves make an issue of it, there really is no big need to stock upon sex specific things (clothing/toys, etc.) prior to birth.
Having said that if you do happen to know and want to have a little fun with it - have at it and enjoy.
Having said that if you do happen to know and want to have a little fun with it - have at it and enjoy.