One of the most obvious symptoms of twins is elevated hCG levels. This pregnancy hormone, also known as human chorionic gonadotropin, is released during the early stages of pregnancy to help the placenta develop. A woman’s urine may contain elevated hCG levels six days after conception. Although these symptoms may not always be a sure sign of twin pregnancy, they should not be overlooked. If you are expecting twins, you may have noticed that your appetite is much more intense than usual, and you’re eating more than you normally do. Your belly is also larger, and you’ve probably noticed a spike in your levels of hCG, the main hormone of pregnancy.