Clomid

I’m on my 3rd round of Clomid (150 mg). The first round was 50 mg and I ovulated but my progesterone was only 13.5. My doctor says it needs to be 16 or higher to sustain pregnancy. My second round was 100 mg and I didn’t ovulate at all and my progesterone level dropped to 3.75. It makes no sense to me and I’m so discouraged. My husband and I have been trying for two years. I was diagnosed with endometriosis the year we got married (2016). I had an HSG done and labs done before I started taking Clomid and everything looked good and my husband had a semen analysis and everything was fine with him. I have my progesterone drawn again November 29th and if I don’t get pregnant this time, I have to meet back with my OB to discuss other options but I’m to the point where I just want to take a break for awhile. Has anyone had a similar experience?