Increased Progesterone on Cycle Day 31, but Negative Pregnancy test - still no period

Ok, so this past month/cycle was unmedictaed due to a surgery my Infertility Doc. wanted to preforming. On CD 25, she did an ultrasound and said that I did ovulate, but still I hadn't started my period.  My progesterone came back 11 that day, but negative for pregnancy.  The following week, CD 31, she had me come back for blood work; I still hadn't started my period and my progesterone had increased to 16.92.  I'm now CD 37 with no period; I go in again this Wednesday, tomorrow, CD 38, for more blood work.  Has anybody experienced anything like this?  Were you pregnant?  Or, what caused the progesterone increase?