The Pregnancy tests detects the pregnancy hormone which is the human chorionic gonadotropin (hCG), in your urine. Within nine days after fertilization, the fertilized egg moves down the fallopian tube into the uterus and attaches (implants) to the uterine wall. Once the fertilized egg implants, the developing placenta begins releasing HCG into your blood. Some HCG also gets passed in your urine. HCG can be found in the blood before the first missed menstrual period, as early as six days after implantation.
Due to this, the best time for her to take the home pregnancy test to avoid false negatives results would be after a week from her menses due date. She should also confirm the results with a Blood pregnancy test done by her health care provider.
These Q&A’s are for educational purposes and should not be relied upon as a substitute for medical advice you may receive from your physician. If you have a medical emergency, please call 911. These answers do not constitute or initiate a patient/doctor relationship.