Is it true that if you want a girl you should have intercourse a couple days before ovulation and if you want a boy is should be the day before or the day of ovulation? How about if you have had intercourse 2 to 3 days before ovulation and then the day of ovulation?
I learned in college that the sperm for boy babies swim faster, but those for girls live longer. If you hope for a girl, time it for 1 or 2 days ahead of ovulation. The closer to ovulation that the sperm arrive, the better the chances are for a boy. No guarantees!!
Boy sperm do swim faster, but die quicker and girl sperm swim much slower but live longer. So theoretically it should work out that if you wanted a boy you should have sex right at ovulation and earlier for a girl, but I think that works very very rarely! It's pretty much just up to chance!