Not Ovulating & low progesterone

Hi ladies. Any one know what causes you to not ovulate or have very low progesterone levels causing infertility? I've been Ttc for over 2 years, just did my first round of clomid and found out my progesterone bood work was at a 2 day 17 of cycle after 5 days of clomid. Doc is increasing clomid cycle 2 and said nothing to worry about - but should I be asking more questions? Why am I not ovulating, why such low progesterone levels and what are the next steps? Will I ever be able to get pregnant? I'm 33 ttc #1. Often have hot flashes, regular 29 day cycle and apparently low progesterone!