The presence of progesterone does not mean that you are pregnant. Progesterone changes gradually throughout the menstrual cycle. If progesterone rises after ovulation, it is highest on the seventh day after ovulation. Therefore, if the test is performed during the luteal phase after ovulation, when progesterone is elevated, it indicates that progesterone is present and relatively high, but not necessarily pregnancy. If chorionic gonadotropin is elevated in the blood, then pregnancy is confirmed, because chorionic gonadotropin is not elevated in the absence of pregnancy. So if you want to be sure if you are pregnant, you have to check the chorionic gonadotropin.