I have heard that if you want a girl it is best to BD
before you ovulate and before you get positive otk. Usually 2 or 1 day before you ovulate.
Even though there is a chance of a boy a day before ovulation. But boys are usually conceive on the day of ovulation due to them being faster and get to the egg quicker but live shorter.
Female sperms are slower but live longer. They can still be active when you ovulate and you BD 2 days ago.
I have seen a chart somewhere on the net showing you the %'s and the studies completed on the subject. You should google genger selection at conception or something. I hope this helps.
Oh and welcome to the forum.