There is usually no effect on the fetus when you take a progesterone shot for birth control. Progesterone is an essential sex hormone during pregnancy, and for pregnant women with low progesterone, it can lead to poor embryonic development and also cause miscarriage. Progesterone injections are the most commonly used medication to preserve the fetus, which has no effect on the fetus, on the contrary, it can also protect the embryo and stabilize the embryo development, but it should be used under the guidance of a professional doctor. In the early stages of pregnancy, it is necessary to supplement folic acid and vitamins appropriately, pay attention to rest, avoid excessive exertion and physical labor, and regularly undergo obstetric examination to ensure the normal development of the fetus, and should immediately go to the hospital to receive treatment when there is any discomfort.