Even if there is already a delay in menstruation, the test may show an incorrect result. False negatives are more common than false positives. If there is a pregnancy, and the diagnostic device says otherwise, the reasons may be the following:
• a short period (if the test is used early, it is easy to get a negative answer due to the small amount of human chorionic gonadotropin in the urine);
• improper use of the test (if you test in the evening or drink a large amount of liquid beforehand, the urine will be less concentrated);
• overdue device;
• poor-quality test (manufacturers of cheap strip strips often save on the amount of reagent);
• frozen pregnancy (the level of hCG has ceased to increase, and the rejection of the endometrium has not yet begun);
• ectopic pregnancy (when the fetal egg is fixed outside the uterine cavity, the pregnant hormone increases slowly);
• threat of termination of pregnancy.
Weak positive result.
The test may not show pregnancy with a delay simply because it is not there. If the cause of the absence of menstruation is ovarian dysfunction, PCOS or other hormonal disorders, then the likelihood of pregnancy is practically excluded.
A false positive test with a delay also happens, although rarely. The device can show a positive result for the following reasons:
• the expiration date has expired;
• the response was interpreted late (more than 10 minutes for all types of devices, except for electronic ones);
• drugs containing hCG were used (often happens when ovulation is stimulated);
• the woman has hormonal diseases;
• there is an oncology of the ovaries.