Hey, L.-
The procedure referred to by someone earlier to check blockage in the tubes is called a Hysterosalpingograms. I also had one, but everything turned out fine. I'm not sure about progesterone levels to get pregnant, but I know to carry an embryo once you've conceived, they like levels to be around 15. When I was tested, mine were 5-8. As a result, they gave me a shot of progesterone when I ovulated, then again on days 4 and 9 (I think- it's been awhile) to keep my levels up to make sure I didn't miscarry. Then, when I found out I was pregnant they kept me on progesterone through the first 10 weeks until the placenta took over feeding the baby. The second time around, I still did it at ovulation and through the first two weeks, but by then my body kicked in and the numbers were through the roof (also due to twins) but didn't have to stay on progesterone the first 10 weeks as they were high enough on their own.
Not sure if the other drug you're referring to is Femara? That's what I was on instead of clomid. (Femara was developed for breast cancer patients, but found to have the same effects as clomid for releasing additional eggs, but with fewer side effects).
We now have a boy who will be 3 in Oct. and twins (boy/girl) who will be turning one the end of July. Good luck to you!