Amniocentesis the kind of testing, with the help of which your doctor may not only determine your future baby’s sex, but this procedure is generally conducted in order to see if there is any chromosomal disorder the fetus may be having, or for the fetal lung maturity determination.  
The very procedure of the Amniocentesis includes a small needle being placed through the abdomen into the uterus in order to collect a little bit of amniotic fluid. The needle is guided away from the baby and the placenta with the help of ultrasound.

You should have the Amniocentesis procedure conducted during the following terms of your pregnancy:
If you want to know the sex of the baby, the Amniocentesis is usually conducted after the 14th week of pregnancy;
If you want to know if the baby, you are carrying has any chromosomal disorder or not, then the period of this procedure conducting is somewhere around the 11th week of your pregnancy;
And, finally, if you care about your baby’s lungs’ maturity, you will have to undergo the Amniocentesis procedure only after the 34th week.

Chorionic Villus Sampling is the kind of testing, with the help of which your doctor may not only determine your future baby’s sex, but this procedure is generally conducted in order to see if there is any kind of chromosomal disorder the fetus may be having.
The very procedure of the Chorionic Villis Sampling includes a small needle of a catheter being placed either through the abdomen or through the vagina near the uterus in order to collect a small sample of villi. The needle or the catheter is guided away from the baby and the placenta with the help of ultrasound.
You should have the Chorionic Villis Sampling procedure conducted somewhere after the 8th week of your pregnancy.
There is the disadvantage of the Chorionic Villis Sampling testing, which is the 3 – 5% miscarriage rate associated with this kind of procedure, though the specialists consider the risk of this testing is more in line with the 1 – 2% from the Amniocentesis analysis. However, this varies greatly by the doctor, and it mainly depends on his or her experience level. 

Old Wives Tales. Yes, nowadays it also exists. There are bunches of people, who will tell you how to get to know about your future baby’s sex without any medical investigation. Among the most common ways are predicting the baby’s sex with the help of your and your husband’s wedding rings’ spinning or swaying; the size and the shape of your belly will also let someone know whether you are expecting a boy or a girl. It may be a lot of fun to conduct these kinds of tests, while they are neither accurate nor dangerous in predicting whether you are expecting son or daughter. The only thing you are to be careful with is any sketchy tests, which include chemicals!

Chinese Lunar Calendar is based on the age of the future mother at the period of conception and on the month of conception. If you are pregnant or planning to have a baby, you may possibly calculate whom to conceive. However, this method should also be used just for fun, as it is hardly to call 100% accurate. Moreover, many people claim, that the failure is caused by the fact that the Chinese consider a newborn baby one year of age. 
There are also specialists, who say that looking at the heart beatings rate of your unborn baby; it is possible to see if you are expecting son or daughter. It is believed, that above 140 heartbeats means a girl, and below is a boy.