The accuracy of a pregnancy test depends on the level of hCG (human chorionic gonadotropin) hormone in your body. It takes time for hCG levels to rise after conception, so taking a test too early may result in a false negative. Generally, most home pregnancy tests can detect hCG levels at around 10-14 days after conception or about 4-5 days before your missed period. However, the accuracy increases if you wait until the first day of your missed period or later. If you have irregular periods or are unsure about when you ovulated, waiting at least one week after your missed period is recommended to get more reliable results. In some cases, it's possible that the app miscalculated your gestational age based on average cycle lengths and ovulation dates. If you continue to experience symptoms of pregnancy and still receive negative results after waiting for an appropriate amount of time, it's advisable to consult with a healthcare professional for further evaluation and testing.