It's an old belief that a baby born after ovulation will be a boy, but scientific evidence shows this isn't true. While some people believe this, science has no firm way of determining whether a pregnancy after ovulation will be a boy or a girl.

Additionally, many people believe this statement is based on the "sour baby, hot girl" theory, which states that a mother becomes more acidic when pregnant with a boy and more alkaline when pregnant with a girl. However, this statement has no scientific basis because it does not prove that conceiving a boy or girl is determined by the mother's diet.

Therefore, we should respect science and not make excessive speculations and fantasies about conceiving a boy or girl. The most important thing is that we should cherish the health of ourselves and our babies, abide by the principles of pregnancy health care, and ensure the health of ourselves and our babies.