A more accurate sign of failed implantation is the onset of menstruation, indicating that the sperm failed to combine with the egg to form a fertilized egg. The fertilized egg usually starts to implant on the 7th day after intercourse during ovulation, and the process of implantation is completed in about 10 to 14 days. Successful implantation of the fertilized egg indicates successful conception, and the usual regular menstruation will no longer occur. If the fertilized egg fails to implant, the proliferated uterine lining will peel off and bleed under the action of progesterone and estrogen, resulting in menstruation and the next menstrual cycle. The performance of menstruation after the failure of implantation is generally no different from that of normal menstruation. If a pregnant woman wants to know whether she has succeeded in implantation, she can make a judgment by observing whether her menstruation comes on time. If a woman experiences delayed menstruation and pregnancy reactions such as nausea and vomiting after intercourse, it is recommended that she consult a doctor in time and complete the relevant examinations under the doctor’s guidance to determine whether she is pregnant.