Clomid and Progesterone?

Rose

I had prog tested this week and it's low :( Dr already suggested starting Clomid next month. When I had my ultrasound done there was mentioning of the combo prog and Clomid as treatment. Anyone else had to have both for treatment? Also, how did you take progesterone? I've read that a lot of people do the shot since the pill isn't as effective. Any advice??