Advice Please or Own Experience

I just recently found out I was pregnant. I went for blood work and was called today. My HCG levels are normal but my progestorne was low. Like 3 when it was supposed to be an 18. My OBGYN prescribed be progestrium 3x daily. I've had no cramps or spotting. 
​Please tell me has had a good outcome with this. I'm so worried. I'm praying it all goes well.