The beta hCG value of 316 after 12 days of embryo transfer can provide some insight into the type of pregnancy, whether it is a single or twin pregnancy. However, it is important to note that this value alone cannot definitively determine the number of embryos implanted. Generally, in a singleton pregnancy, the beta hCG levels tend to double every two to three days during early pregnancy. In contrast, in a twin pregnancy, the levels may rise more rapidly and be higher than expected for a singleton pregnancy. It is recommended to consult with your healthcare provider who will consider additional factors such as ultrasound results and other clinical indicators to accurately determine if you are carrying one or two embryos.