If fertilization has occurred, by ten days past ovulation, 10 DPO, most people will have gone through implantation. Implantation is the beginning of pregnancy, when the blastocyst, or ball of cells, has embedded into the uterine lining. Some people say that they experience symptoms when implantation happens, but many of these symptoms, like cramping and spotting, can also be premenstrual symptoms. How can you tell the difference? Here’s what you need to know at 10 DPO.