The fertilized egg does not necessarily cause stabbing pains in the stomach and may be asymptomatic. Fertilization occurs within 24 hours after ovulation, and the fertilized egg will be implanted in the uterine lining 6-7 days after its formation. During the process of implantation, some pregnant women may show slight stabbing pain in the lower abdomen, accompanied by a small amount of vaginal bleeding, which usually lasts for 3-4 days, which is a normal physiological phenomenon and does not require special treatment. However, there are still some pregnant women who do not have any performance during the implantation period. Generally, HCG (human chorionic gonadotropin) starts to be secreted about 1 day after the fertilized egg has been laid, and pregnancy can be determined by blood HCG test about 10 days after intercourse, or urine HCG test about 2 weeks after intercourse. Intrauterine pregnancy can be determined by ultrasound at about 40 days after menopause, as prescribed by your doctor.