It is all chance. But an old wives' tale is to have sex the actual day you ovulate to increase the chances of a boy. Why? Because the sperm that carry the Y-chromosome (which makes a baby a boy) are faster but more sensitive than the X-chromosome sperm (which make girls). So if you have sex the day you ovulate those faster sperm can reach the egg before dying off.
But again, it's all chance. Even having sex the day of ovulation can result in a girl.
I don't think YOU ( your ovulation days) can decide the sex. It's all up to your partner whether or not a Y chromosome sperm makes it to your egg ( a boy) or an X ( a girl). Although it might be fun for you and your partner to try, I think it's all left to chance. Good luck!
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