There's a blood test that you can get after 9 weeks, either at your doctor's office or at home with a kit bought online, where you give a sample of your blood and they're able to isolate your baby's DNA and tell you if they have XX (female) or XY (male) chromosomes. I used the brand sneak peak with my son (currently 3) and it gave me my test results a week after I sent the sample back. It's just a lancet prick, like diabetics test their blood sugar with, so it doesn't even hurt.