If you are pregnant and experience a decrease in progesterone, progesterone can be given to increase the level of progesterone, which has the effect of preserving the fetus. If you are not getting your period for a long time, you can take progesterone and then wait for your period to come, so progesterone is more useful. If you have ureteral stones, you can also be treated with progesterone, which is very effective in treating urinary stones because it has the effect of relieving smooth muscle spasm. If you experience lower abdominal pain after pregnancy, which is a symptom of preterm miscarriage, progesterone can also relieve uterine contractions and play a role in preserving the fetus.