Pregnancy can usually be detected when menstruation is delayed for 6 days; in a few cases where the pregnant egg is deposited late, it may not be detected.
After the egg is discharged, it usually survives for 24 to 48 hours in the woman’s body, and the sperm enters the woman’s body and survives for about 24 to 72 hours, so conception usually occurs 3 days before and 4 days after ovulation.
If conception occurs, the fertilized egg will usually be deposited within 7 days after conception. After the fertilized egg is deposited, the pregnant woman’s body will secrete human chorionic gonadotropin (HCG). The hormone enters the bloodstream 24 hours after the fertilized egg is laid and is detected in the urine one week after the egg is laid.
Menstruation usually occurs 14 days after ovulation, so pregnancy can usually be detected in the blood or urine if conception occurs normally, and yolk sacs may be seen on gynecological ultrasound if the egg is deposited early.
However, in a few cases where the egg is deposited late, the timing of the secretion of human chorionic gonadotropin and the visualization of the yolk sac in the ultrasound will be wrong, and if the menstrual period is pushed back by 6 days, the pregnancy may not be detected in the urine or the ultrasound. Consult your doctor for details.