A day 21 Progesterone test is typically performed around day 21 of a 28-day menstrual cycle to assess Progesterone levels in the luteal phase and evaluate ovulation. While a day 21 Progesterone test can help determine if ovulation has occurred, it is not a definitive indicator of pregnancy. If conception has occurred, Progesterone levels will continue to rise to support the pregnancy. However, Progesterone levels alone cannot confirm pregnancy. The most reliable way to confirm pregnancy is through a pregnancy test, which detects the presence of the hormone human chorionic gonadotropin (hCG) in the body. hCG is produced by the developing placenta and is an indicator of pregnancy. If you suspect you may be pregnant, it is recommended to take a pregnancy test or consult with a healthcare professional for accurate confirmation. They can provide appropriate testing and guide you through the process of confirming pregnancy based on your individual circumstances.