The only way to tell whether or not a fetus is a male or a female is to get a sonogram once the baby or fetus develops enough in the mothers womb.
The Ultrasound or Sonogram can tell the gender of the fetus between 18 to 22 weeks into the pregnancy.
However before then there are some symptoms that may lead to you knowing whether or not the fetus is a male or female.
Some signs and symptoms that you may be having a boy during pregnancy are no morning sickness during early pregnancy, you are craving salty or sour foods, your carrying low, your areolas have darkened considerably, your belly looks like a basketball, you're are carrying the extra weight out front, or your babies heart rate is less than 140 beats per minute.
However these symptoms are no guarantee that you're gonna have a boy instead of a girl.
However most women who do experience the above symptoms during pregnancy do eventually have a boy when the baby gets to full term.
The only real way to know for sure whether a baby is gonna be a boy or girl is to have a sonogram and see the actual fetus or baby inside the womb.
But sometimes certain signs and symptoms can be indicators of having either a boy or girl.