Progesterone question

So I just got my progesterone results back and it's at a 9. I have had a previous miscarriage at 6 weeks, I'm about 5 wks now. My question is since I'm not at 15-20 why wouldn't I get prescribed progesterone to try and save this pregnancy if it needs saving because of the low result? Is this something I should get another opinion on? I'm not spotting or bleeding of any kind. Just think it's weird that she doesn't want to prescribe me anything.