The best way to find out what sex your child will be is to see its genitalia features on ultrasound -- easily with a boy! Nothing about movement or the position of the child in utero will give you a clue. I am not familiar with the term "necklace" -- but you might ask your doctor if there are other ways to check the sex! My daughter had her first child in 1998, and she didn't want to know the sex. So, my granddaughter ended up getting a lot of GREEN and YELLOW clothing from Grandma and Grandpa. I didn't even ask about the sex of the second child when my daughter got pregnant again. Good news! She called in the second trimester and said, "It's a boy! We saw his 'equipment' on the ultrasound."