If you know the exact date you conceived, you might be able to determine the sex of your baby. If you currently are trying to conceive, keeping track of your basal body temperature and dates of intercourse will help you greatly. If you are already pregnant, this information, if you have it, can help you out as well. Even if you did not try to conceive using the Shettles Method, which is designed to help you have either a girl or a boy, you still can use its principles to try to predict the sex of your baby.
Locate the charts you used to track your basal body temperature. (Your waking temperature, plotted on a graph, can help determine the day of ovulation.)
Look at the date you conceived. For example, say your ovulation date was July 20. Note which days you had intercourse during cycle-say July 19 and July 20.
Use the Shettles Method to determine what sex your baby might be. The concept behind the Shettles Method is that sperm with X chromosomes are slower but stronger and take longer to get to the egg, while Y sperm are faster but die more quickly. Thus, having sex the day of or the day before ovulation should increase the chances of having a boy. Having sex two or three days before ovulation (or even as many as five days) can result in a girl. Using the dates of intercourse in the example above, you most likely conceived a boy.
If you are trying to conceive, you probably are having sex every day or every other day, unless you are specifically using the Shettles Method. This might make it impossible to determine the sex of the baby before you get your gender ultrasound.