Just another question on the whole boy Vs. girl thing..

"They say" that if you DTD before you O then its more than likely you get a girl as the girl sperm lives longer.. and if you DTD after you O just once, youre more than likely to get a boy as the boy sperm swims faster.

So my question is, has this proven to work, or not work, for those who know when bubs was conceived?

I know that at the end of the day its really a 50/50 chance either way, but just curious.

TIA!