The million dollar question for many after finding out about a pregnancy: Am I having a boy or a girl?

Some people love the suspense of not knowing the sex of their baby until the delivery. But others can’t wait and find out much sooner.

Of course, only a doctor can reliably determine the sex of a baby. Yet, this doesn’t stop many from predicting the sex of their baby based on factors like how they carry the baby or what they’re craving to eat.

Here’s what you need to know about methods used to determine a baby’s sex, as well as how some people use old wives’ tales to guess the sex.

When it comes to finding out the sex of your baby, there isn’t one single test that is used for everyone. So if you want to know the sex ahead of time, your doctor can use different tests at different stages of your pregnancy.

But while all of these tests are reliable, they’re not all suitable for everyone. Some of them carry significant risks. For most of the tests listed, finding out the sex is a secondary benefit while the test looks for other information.

The following are possible ways to learn your baby’s sex, from the earliest options.

In vitro fertilization with sex selection

If you’re planning in vitro fertilization (IVF), there’s an option to choose the sex of your baby in conjunction with this procedure. IVF assists with fertility by combining a mature egg with sperm outside of the body. This creates an embryo, which is then implanted in the womb.

If you choose, you can have the sex of different embryos identified, and then only transfer the embryos of your desired sex.

This might be an option if it is important to you to have a child of a certain sex.

Sex selection in conjunction with IVF is about 99 percent accurate. But, of course, there’s the risk of multiple births with IVF — if you transfer more than one embryo to the uterus.

Non-invasive prenatal test

A non-invasive prenatal test (NIPT) checks for chromosomal conditions like Down syndrome. You can have this test starting at 10 weeks of pregnancy. It doesn’t diagnose a chromosome disorder. It only screens for the possibility.

If your baby has abnormal results, your doctor may order further tests to diagnose Down syndrome and other chromosome disorders.

For this test, you’ll provide a blood sample, which is then sent to a lab and checked for the presence of fetal DNA linked to chromosome disorders. This test can also accurately determine the sex of your baby. If you don’t want to know, let your doctor know before testing begins.

You’ll need the NIPT if you’re at high risk of having a baby with a chromosome abnormality. This might be the case if you’ve previously given birth to a baby with an abnormality, or if you’ll be over the age of 35 at the time of delivery.

Because this is a noninvasive test, giving a blood sample doesn’t pose any risk to you or your baby.

Chorionic villus sampling

Chronic villus sampling (CVS) is one genetic test used to identify Down syndrome. This test removes a sample of chorionic villus, which is a type of tissue found in the placenta. It reveals genetic information about your baby.

You can have this test as early as your 10th or 12th week of pregnancy. And because it has gene information about your baby, it can also reveal the sex of your baby.

Your doctor may advise CVS if you’re over the age of 35 or if you have a family history of a chromosome abnormality. This is an accurate test for finding out the sex of the baby, but it does involve some risks.

Some women have cramping, bleeding, or leak amniotic fluid, and there’s also the risk of miscarriage and preterm labor.

Amniocentesis

Amniocentesis is a test that helps diagnose detect developmental issues in a fetus. Your doctor collects a small amount of amniotic fluid, which contains cells that indicate abnormalities. The cells are tested for Down syndrome, spina bifida, and other genetic conditions.

Your healthcare provider may recommend an amniocentesis if an ultrasound detects an abnormality, if you’ll be older than 35 at the time of delivery, or if you have a family history of a chromosome disorder. You can have this test around 15 to 18 weeks of pregnancy, and it takes about 30 minutes.

First, your doctor uses an ultrasound to determine your baby’s location in the womb, and then inserts a fine needle through your abdomen to withdraw amniotic fluid. Risks include cramping, bruising, and spotting. There’s also a risk of miscarriage.

Along with detecting birth defects and other abnormalities with your baby, an amniocentesis also identifies the sex of your child. So if you don’t want to know, make this known before testing so your doctor doesn’t spill the beans.

Ultrasound

An ultrasound is a routine prenatal test where you’ll lie on a table and have your stomach scanned. This test uses sound waves to create an image of your baby, and it’s often used to check your baby’s development and health.

Since an ultrasound creates an image of your baby, it can also reveal the sex of your baby. Most doctors schedule an ultrasound at around 18 to 21 weeks, but the sex may be determined by ultrasound as early as 14 weeks.

It’s not always 100 percent accurate, though. Your baby might be in an awkward position, which makes it difficult to clearly see the genitals. If the technician can’t find a penis, they’ll conclude that you’re having a girl and vice versa. But mistakes do happen.

At-home testing kits

Along with traditional methods, some people have a positive experience using at-home kits marketed as “early baby gender blood tests.”

Some of these tests (according to claims) can determine the sex as early as 8 weeks, with about 99 percent accuracy. However, these are claims made by the companies and there isn’t research to back up these statistics.

This is how it works: You take a sample of your blood, and then send this sample to a lab. The lab checks your blood sample for fetal DNA, looking specifically for the male chromosome. If you have this chromosome, you’re supposedly having a boy. And if you don’t, you’re having a girl.

Keep in mind that when sending samples through the mail to an unknown lab there are many factors that may reduce the reliability of the results. These tests tend to be expensive so you may want to consider whether they are worth the cost for you.

Old wives’ tales

Some people even use old wives’ tales to predict their baby’s sex. According to folklore, if you’re extra hungry during pregnancy, you’re probably pregnant with a boy. It’s believed that extra testosterone secreted by a baby boy increases appetite.

There’s even the belief that a higher fetal heartbeat (over 140 bpm) means you’re having a girl. And that you’re carrying a girl if you’re forgetful during pregnancy. Some even believe that you’re having a boy if your belly is low and a girl if your belly is high.

But while old wives’ tales are a fun way to predict the sex of a baby, there isn’t any science or research to back up these beliefs or claims. The only way to know what you’re having is to schedule an appointment with your doctor.

Learning the sex of your baby can be exciting and can help you prepare for your baby‘s arrival. Some couples, though, enjoy the anticipation and only learn the sex of their baby in the delivery room — and that’s perfectly okay.