Low progesterone :/

They ordered me some blood work Tuesday to check my hcg levels and progesterone. I was having a little spotting. My hcg levels still detected early pregnancy, so I think that's good. My progesterone level is low which can cause miscarriage.. They prescribed me progesterone tablets to help. I go get more blood work done today to compare the two and make sure my levels are rising. I won't have the results til tomorrow. Please pray. I'm nervous as heck! Has anyone else had this problem? What happened?