Been told ya gotta wait until the second week after the period to turn out boys. Interesting, considering the jewish law laid out in Leviticus, with regards to when intercourse was allowed versus unclean. Never heard it until after we stopped with the having kids thing, so no proof here. Fella that told me said his info had helped a few guys get a son that way, he had done a pretty serious study of genetics and associated subjects. Who knows? I will say, with the biblical emphasis on sons, it wouldn’t surprise me for God to tilt the scales to that end when laying down the law.
