I'm currently 22 weeks pregnant, and still don't know the sex... When will I find out?

Ultrasound. If someone wants to know the sex of their fetus, usually that happens at the time of an ultrasound done at about 20 weeks. Sometimes the fetus is in a position that makes it difficult to see what sex it is, but most of the time it is possible. Your prenatal provider may be able to tell you by looking at your ultrasound report.