Has anyone tried this? Was it wrong or right? I have two boys and was desperate to find out the sex of my third baby, so ordered this test from DNA Worldwide. You need to be at least eight weeks pregnant. You have to prick your finger then put drops of blood on a card, which is sent off to a lab in America. They can then see if DNA from a male foetus is present in your blood. If positive for male DNA - you're having a boy, if not, it's a girl. According to the test results, I'm having another boy. I'll know for sure at my 20 week scan later this week. HOwever, since I got my result I've done some research and discovered that many women have been given the wrong result. Let me know if you've tried it or know more about the science behind it...