According to the Chinese Lunar Calandar, if you add your age at conception to the month you are due, you are suposed to know what sex you are having: if it's an even number it's a girl and if it's an odd number, it's a boy! I got 30 with my first pregnancy and this one, so it was correct first time around and apparently I am having another girl. Apparently it's pretty accurate but I doubt it! Try it for fun and post your results!