I did the chinese gender chart you did and put in 2 different conception dates as I don't know exactly when I O'd and I got 2 different genders! I definitely know it will be a boy or a girl!!
Mocha, we both have scans on the 28th, but mine is my 20 week one and we don't think we will find out gender (though I haven't ruled it out 100% yet).
In-laws have been here 24 hours and are already driving me crazy!! Only one more night with us and then they are staying nearby- phew.